An account by a former employee of the security team hired by Ms. Spears’s father created the most detailed portrait yet of the singer’s life under 13 years of conservatorship.Britney Spears’s father and the security firm he hired to protect her ran an intense surveillance apparatus that monitored her communications and secretly captured audio recordings from her bedroom, including her interactions and conversations with her boyfriend and children, according to a former employee of the security firm.Alex Vlasov, the employee, supported his claims with emails, text messages and audio recordings he was privy to in his nine years as an executive assistant and operations and cybersecurity manager for Black Box, the security firm. He came forward for a new documentary by The New York Times, “Controlling Britney Spears,” which was released on Friday.Recording conversations in a private place and mirroring text messages without the consent of both parties can be a violation of the law. It is unclear if the court overseeing Ms. Spears’s conservatorship was aware of or had approved the surveillance. Mr. Vlasov’s account, and his trove of materials, create the most detailed portrait yet of what Ms. Spears’s life has been like under the conservatorship for the past 13 years. Mr. Vlasov said the relentless surveillance operation had helped several people linked to the conservatorship — primarily her father, James P. Spears — control nearly every aspect of her life.“It really reminded me of somebody that was in prison,” said Mr. Vlasov, 30. “And security was put in a position to be the prison guards essentially.”In response to detailed questions from The Times, a lawyer for Mr. Spears issued a statement: “All of his actions were well within the parameters of the authority conferred upon him by the court. His actions were done with the knowledge and consent of Britney, her court-appointed attorney, and/or the court. Jamie’s record as conservator — and the court’s approval of his actions — speak for themselves.”Alex Vlasov, a former employee of Black Box Security, decided to share his information after hearing Ms. Spears’s speech to the court in June. He said a surveillance operation had helped several people linked to the conservatorship control nearly every aspect of Ms. Spears’s life.Victor Tadashi SuarezEdan Yemini, the chief executive and founder of Black Box Security, also did not respond to detailed questions. In a statement, his lawyer said, “Mr. Yemini and Black Box have always conducted themselves within professional, ethical and legal bounds, and they are particularly proud of their work in keeping Ms. Spears safe for many years.”Ms. Spears’s lawyer, Mathew S. Rosengart, said in a statement: “Any unauthorized intercepting or monitoring of Britney’s communications — especially attorney-client communications, which are a sacrosanct part of the legal system — would represent a shameful violation of her privacy rights and a striking example of the deprivation of her civil liberties.”“Placing a listening device in Britney’s bedroom would be particularly inexcusable and disgraceful, and corroborates so much of her compelling, poignant testimony,” Mr. Rosengart said. “These actions must be fully and aggressively investigated.”Mr. Vlasov said his superiors had often told him that the severe surveillance measures were necessary to properly protect Ms. Spears and that she wanted to be in the conservatorship. He said he had felt compelled to share his information after hearing Ms. Spears’s comments to the court in June, when she excoriated the judicial system, her conservators and her managers. She called the arrangement abusive.Ms. Spears’s father, who is known as Jamie, was appointed conservator in 2008, shortly after Ms. Spears was twice taken to the hospital by ambulance for involuntary psychiatric evaluations amid a series of public struggles and concerns around her mental health and potential substance abuse. He was given broad control over her life and her estate, including the power to retain round-the-clock security for Ms. Spears.Mr. Spears and others involved in the conservatorship have insisted that it was a smooth-running operation that worked in the best interest of his daughter. But in the wake of Ms. Spears’s comments in court in June, the judge authorized her to choose her own lawyer, Mr. Rosengart, for the first time. Mr. Rosengart swiftly filed to remove Mr. Spears as the conservator of the singer’s estate. After consistently arguing that there were no grounds for his removal, Mr. Spears abruptly asked the court on Sept. 7 to consider whether to terminate the conservatorship entirely.Mr. Rosengart’s and Mr. Spears’s requests are expected to be considered at a hearing scheduled for Sept. 29.The security companyThe security team’s role has long been a mystery.Mr. Yemini, the Black Box Security founder, was born in Israel, and is described on a company website as having a background in the Israeli Special Forces. The Spears account helped Black Box grow from a tiny operation to a prominent player in the celebrity security industry. It counts the Kardashians, Miley Cyrus and Lana Del Rey among its clients.Mr. Vlasov joined Black Box in 2012 as a 21-year-old college student, excited by the opportunity to master the security industry. He started as Mr. Yemini’s assistant and grew into a role that encompassed wide responsibilities over operations and digital management. “I did everything from write his messages, write his emails, to be on all phone conversations in order to take notes for him,” Mr. Vlasov said. “I was the only person at Black Box that knew everything, really.”He generally worked at Black Box’s office in the Woodland Hills area of Los Angeles and seldom saw Ms. Spears in person, he said. But through the surveillance apparatus and his close work with Mr. Yemini and his colleagues, Mr. Vlasov said, he had a uniquely comprehensive view of her life.Edan Yemini with Ms. Spears in 2009. Mr. Yemini is the chief executive and founder of Black Box Security.AlamyMr. Vlasov said that Ms. Spears’s phone had been monitored using a clever tech setup: The iCloud account on her phone was mirrored on an iPad and later on an iPod. Mr. Yemini would have Mr. Vlasov encrypt Ms. Spears’s digital communications captured on the iPad and the iPod to send to Mr. Spears and Robin Greenhill, an employee of Tri Star Sports & Entertainment Group, the former business manager for the singer’s estate.This arrangement allowed them to monitor all text messages, FaceTime calls, notes, browser history and photographs.“Her own phone and her own private conversations were used so often to control her,” Mr. Vlasov said.In response to questions about the surveillance operation, a lawyer for Tri Star Sports & Entertainment Group said: “These allegations are not true. Ms. Greenhill was only involved in Ms. Spears’ security to the extent Ms. Spears requested her involvement, as well as Tri Star’s role of issuing the payments to the security company.” The lawyer did not respond to follow-up questions specifically asking whether Ms. Greenhill had ever received copies of or reports on the contents of Ms. Spears’s text communications.Mr. Vlasov said the reason Mr. Yemini had given for monitoring Ms. Spears’s phone was to protect her from harm and bad influences. But Mr. Spears monitored his daughter’s text-message conversations with her mother, her boyfriend, her close friends and even her court-appointed lawyer, according to screenshots of messages provided to The Times.Mr. Vlasov’s accounts of how Ms. Spears’s life was controlled by the security team were confirmed by others with firsthand knowledge of the conservatorship who requested anonymity. They said Ms. Spears essentially could not leave her home without the presence of security personnel, who would inform Mr. Yemini, Mr. Spears and Ms. Greenhill of the singer’s movements via group chat.Ms. Spears with her father in 2013. As part of the conservatorship, Mr. Spears was given broad control over his daughter’s life and her estate, including the power to retain round-the-clock security.RS-Jack/X17online.comAs conservator of the estate, Mr. Spears controls his 39-year-old daughter’s nearly $60 million fortune and has the authority to employ workers for her.Mr. Vlasov said Mr. Yemini and another Black Box employee had once given him a portable USB drive and asked him to delete the audio recordings on it.“I had them tell me what was on it,” Mr. Vlasov said. “They seemed very nervous and said that it was extremely sensitive, that nobody can ever know about this and that’s why I need to delete everything on it, so there’s no record of it. That raised so many red flags with me and I did not want to be complicit in whatever they were involved in, so I kept a copy, because I don’t want to delete evidence.”The drive, he discovered, contained audio recordings from a device that was secretly placed in Ms. Spears’s bedroom — more than 180 hours of recordings. Mr. Vlasov said he had thought the timing was curious because some of the recordings were made around the time that a court investigator visited Ms. Spears to perform a periodic review in September 2016.The New York Times reviewed the recordings to confirm their authenticity.When asked why he had continued working with Black Box despite harboring so many concerns, Mr. Vlasov said he had feared the amount of power Mr. Yemini and others had, and the possibility that they could damage his job prospects in the industry.After Ms. Spears’s impassioned remarks to the court in June, Mr. Vlasov said, his mind-set changed.Choosing to leave Black Box in April was the best decision of his life, he said, and he believes going public is the right thing to do. “I don’t know what’s going to happen tomorrow, but I’ve never regretted it,” he said.‘She did not want to be there’Ms. Spears spent time at a mental health treatment facility in 2019 — a stay that appears to have been a turning point in the conservatorship. Who exactly sent her there, for what reason and whether she went on her own volition are in dispute.Mr. Spears and others involved with the conservatorship have said that she consented to go to the facility and that she was aware that no one could force her to stay. Conservators are not allowed to force a conservatee into a mental health treatment facility against their will.“She did not want to be there,” Mr. Vlasov said. “I heard this from multiple people, including Robin and Jamie themselves when they would talk on the phone to Edan. I overheard multiple conversations where they knew Britney didn’t want to be there.”The Times obtained text messages that Ms. Spears had sent from the facility that said she felt she was there involuntarily and that she could not leave, noting that security personnel were at the door at all times. Ms. Spears told a judge later in 2019 that she had felt she was forced into the facility, according to a transcript of the closed-door hearing. She repeated that claim to the court publicly in June.Mr. Vlasov shared digital communication that showed how Ms. Spears, while in the facility, had tried to hire a new lawyer to replace her court-appointed lawyer — and that Mr. Spears and others had monitored that effort.Ms. Spears with Robin Greenhill, an employee of Tri Star Sports & Entertainment Group. Mr. Vlasov said that Ms. Spears’s phone had been monitored using a clever tech setup: The iCloud account on her phone was mirrored on an iPad and an iPod.AlamyThe prospective lawyer asked Ms. Spears if he could come talk to her. Ms. Spears responded that she didn’t think the security personnel would let her see him. “They will say no for sure to me seeing a new lawyer on my side,” she said, and proposed that he tell the security personnel that he was a plumber instead. The lawyer declined that plan. “You have to be approved by the court before I hire you, but I don’t understand how can I know I want to hire you unless I meet with you first?” Ms. Spears wrote.“Yes, it’s a Catch-22 situation,” the lawyer said.In a text message sent a week after the initial exchange with the lawyer, Ms. Spears said that Mr. Spears had taken away her phone after finding out that she had been talking to a lawyer.The lawyer confirmed to The Times that the correspondence provided by Mr. Vlasov was accurate.Mr. Vlasov recalled that “one of the biggest ‘aha,’ red-flag moments” in his tenure at Black Box had happened in August 2020, when Ms. Spears’s court-appointed lawyer, Samuel D. Ingham III, sent an email to Mr. Spears’s lawyers and Mr. Yemini asking for written confirmation that Ms. Spears’s new phone was not being monitored.“Ethically, I need to get written confirmation that no one other than my client can access her calls, voice-mail messages or texts directly or indirectly,” Mr. Ingham wrote in the email, which was reviewed by The Times.Geraldine Wyle, a lawyer for Mr. Spears, responded: “Jamie confirms that he has no access to her calls, voice-mail messages, or texts.”Ms. Spears in Paris for her “Piece of Me” tour in 2018. The following year, the singer spent time at a mental health treatment facility — a stay that appears to have been a turning point in the conservatorship.Marc Piasecki/Getty ImagesIn response to questions from The Times about the exchange, Ms. Wyle said, “Mr. Spears’ actions have always been proper, and in strict conformity with the law, and the orders of the Los Angeles Superior Court.”Mr. Ingham did not respond to requests for comment.Mr. Spears was particularly interested in Ms. Spears’s boyfriends, Mr. Vlasov said. The security team tailed her boyfriends in a continuing effort to look for incriminating behavior or other evidence that they might be a bad influence on Ms. Spears, he said.“There was an obsession with the men in Britney’s life,” Mr. Vlasov said.Her boyfriends were required to sign strict nondisclosure agreements, Mr. Vlasov said. An agreement signed in 2020 by her boyfriend at the time, Sam Asghari, who is now her fiancé, technically forbade him to post on social media about Ms. Spears without Mr. Spears’s prior written approval.In a confidential report by a court investigator that was obtained by The Times, the investigator wrote in 2016 that Ms. Spears had told her that she could not befriend people, especially men, without her father’s approval and that the men she wanted to date were “followed by private investigators to make sure their behaviors are acceptable to her father.”Mr. Vlasov said that Black Box Security had billed more than $100,000 in 2014 for investigating and surveilling Ms. Spears’s boyfriend at the time. The boyfriend, David Lucado, told The Times that he had been aware at the time that he was being followed by private investigators, and he said he had called 911 twice because of dangerous tailing situations. He said he believed he might have been more of a target because he was encouraging Ms. Spears to understand her legal rights under the conservatorship.‘Free Britney’ draws attentionAnother object of intense interest among those controlling Ms. Spears’s life, Mr. Vlasov said, was the so-called Free Britney movement, a growing cohort of fans that in recent years has brought heightened attention to the conservatorship case. Black Box Security sent investigators to infiltrate the group at a rally in April 2019 and to develop dossiers on some of the more active participants.“Undercover investigators were placed within the crowds to talk to fans to ID them, to document who they were,” Mr. Vlasov said. “It was all under the umbrella of ‘this is for Britney’s protection.’” He shared surveillance photographs with The Times that corresponded to photos posted by Free Britney participants that day.Megan Radford, a member of the so-called Free Britney movement, was classified as “a high risk due to her creation and sharing of information.”via Megan RadfordBlack Box prepared a “threat assessment report” dated July 2020 that included background information on several fans within the movement, including people who had popular podcasts and social media accounts like “Britney’s Gram,” “Eat, Pray, Britney,” “Lawyers for Britney” and Diet Prada. One activist, described as a young mother in Oklahoma, Megan Radford, was classified as “a high risk due to her creation and sharing of information.”An email from August 2020 sent by Mr. Yemini discussed the possibility of surveilling Kevin Wu, a fan who runs the prominent Twitter account Free Britney L.A.“They were extremely nervous, because they had zero control over the Free Britney movement and what’s going to come out of it,” Mr. Vlasov said.The fees for surveilling Ms. Spears’s boyfriend and the Free Britney participants, Mr. Vlasov said, were billed to Ms. Spears’s estate. More