A New York lawmaker on Thursday expressed concern about consumer accusations that Ticketmaster had changed its refund policy in the midst of the pandemic, and asked the state attorney general to open a formal investigation into the company.

A spokesman for the attorney general declined to discuss whether the office had started a formal investigation of the sort requested by State Senator James Skoufis, chairman of the Senate Investigations and Government Operations Committee. But, the spokesman said, “We are already looking into the matter.”

The Attorney General’s office said it had also independently received several complaints from ticketholders about the ticketing industry and delays for refunds on live events hit by the pandemic.

Ticketmaster has denied changing its refund policy, saying that it only clarified language on its website. And Ticketmaster maintains that it acts only on behalf of clients, like concert promoters and venues, that often have the final say about whether to refund tickets.

In a statement this week, Ticketmaster — which is owned by the concert giant Live Nation — said that its clients had already authorized refunds for more than 11,000 concerts and sporting events, including 4,000 that had been postponed.

That announcement came after consumers flooded social media with gripes over their difficulty securing refunds for postponed concerts from Ticketmaster and other big ticket vendors like StubHub, and portrayed those companies as being greedy at a time of need.

AEG Presents, Live Nation’s biggest rival, plans to start a 30-day window on May 1 for fans to request refunds for shows that have been rescheduled. After May 1, they will get 30 days from the time new dates are announced.

According to a document that AEG circulated to talent agents this week, the refunds will be offered for concerts that were postponed once the pandemic shut down the concert world last month, and have been given new dates.

AEG, which is owned by the billionaire investor Philip F. Anschutz, puts on tours by stars like Justin Bieber, Taylor Swift and Celine Dion and owns regional concert promoters like Goldenvoice in Los Angeles, which organizes the Coachella festival.

Around 30,000 events have already been postponed as a result of the pandemic, and tickets to many of those were sold months ago. By some estimates, consumers have spent more than $1 billion on tickets to disrupted events.

Live Nation has not set any specific timing for refunds. But in a statement, the company said: “Live Nation’s plan is to continue offering an opportunity for refunds on all of its rescheduled shows as new dates are set. We anticipate those windows will begin to open up on an event by event basis in the next few weeks.”

The issue of ticket refunds during the coronavirus pandemic has crystallized many longstanding complaints about Live Nation and Ticketmaster, which merged in 2010. A 10-year consent decree, negotiated with the Justice Department to ensure that the combined company would not exert unfair influence over the concert business, was recently extended by five years after an inquiry by federal regulators.

In his letter to the New York attorney general, Letitia James, Mr. Skoufis urged her to look into what he said was a recent change of policy regarding refunds on concerts that have been postponed because of the crisis.

“I ask the Attorney General to intervene in any means necessary, including a criminal inquiry, and strongly urge these corporations to reconsider their newly adopted policies and refund consumers who are struggling to survive,” he wrote.

Mr. Skoufis also said that his committee had since January launched a broader investigation into practices in the ticketing industry. But he said that the cancellation of thousands of concerts since the virus struck had given new impetus to look at Ticketmaster’s practices on refunds.

“Deceptively changing the language of refund policies and excluding postponed or rescheduled events are forms of corporate robbery,” he said in a statement. “Withholding billions of dollars that many now need to survive this pandemic is the antithesis of corporate social responsibility.”

“Ticketmaster is a sales platform and does not hold all customer dollars,” Ticketmaster said in a statement. “Revenue from ticket sales is held by our clients and event organizers. The entire industry is working through these unprecedented times to reschedule as many of the tens of thousands of disrupted events as possible or cancel them.”

“We believe the vast majority of our clients will open full refund opportunities once they have had time to determine if it is realistic to reschedule them or not,” the statement continued, “and we welcome the opportunity to work with legislators and regulators to ensure consumers and the industry are well protected.”

Ticketmaster recently adjusted some of the language on its website about when ticket refunds are available. Whereas a few weeks ago, it said that people can get their money back “if your event is postponed, rescheduled or canceled,” now it only lists cancellation as a basis for refunds, though it suggests there may be other circumstances in which they might be considered. Ticketmaster says this is not a change in policy and that its refund policy has remained the same for years.

Ticketmaster, which processes more than $30 billion in ticket sales each year, acts on behalf of concert venues and promoters. For events that are canceled outright, Ticketmaster says that it offers refunds within 30 days. But for shows that are postponed or whose status is in doubt, it relies on venues and promoters to decide whether tickets should be refunded — and in many of those cases, the promoter or venue may be controlled by Live Nation.

Beyond the refunds for shows that have already been postponed, the concert world — which had expected 2020 to be a banner year — has been in a state of deep anxiety about when artists will be able to tour again, and when the public will feel comfortable with the elbow-to-elbow proximity of an arena or club.

While some events have been rescheduled for later this year, many talent agents and industry executives say that they do not expect tours to resume full-steam until 2021. And in a recent note to investors, Morgan Stanley predicted that it may take until 2022 for Live Nation to return to the level of profitability it had last year.