WASHINGTON — The Treasury Department’s inspector general is investigating whether confidential banking information related to a company controlled by President Trump’s personal attorney Michael Cohen may have been leaked, a spokesman said.

Rich Delmar, counsel to the inspector general, said that in response to media reports the office is “inquiring into allegations” that Suspicious Activity Reports on Cohen’s banking transactions were “improperly disseminated.”

Detailed claims about Cohen’s banking history were made public Tuesday by Michael Avenatti, an attorney for Stormy Daniels, the adult-film star who was paid $130,000 by Cohen shortly before the 2016 election to keep quiet about her alleged affair with Trump.

On Twitter, Avenatti circulated a dossier that purports to show that Cohen was hired last year by the U.S.-based affiliate of a Russian company owned by Viktor Vekselberg, a Russian business magnate who attended Trump’s inauguration and was recently subjected to sanctions by the U.S. government. The affiliate, New York investment firm Columbus Nova, confirmed the payment, saying it was for consulting on investments and other matters, but denied any involvement by Vekselberg.

Avenatti’s dossier also alleged that, after Trump’s inauguration, Cohen’s company Essential Consultants had received payments from several others with business considerations before the federal government, including telecommunications giant AT&T, aircraft manufacturer Korea Aerospace Industries and pharmaceutical company Novartis. All three companies subsequently confirmed the payments.

In an interview, Avenatti declined to reveal the source of his information.

“The source or sources of our information is our work product, and nobody’s business,” Avenatti said. “They can investigate all they want, but what they should be doing is releasing to the American public the three Suspicious Activity Reports filed on Michael Cohen’s account. Why are they hiding this information?”

A fixture on cable television, Avenatti has been calling on the Treasury Department for weeks to release reports of unusual banking transactions by Cohen. He came up with a social media hashtag: #releasetheSAR, using the acronym for a Suspicious Activity Report.

On Tuesday night, Avenatti told CNN’s Anderson Cooper: “There’s been some criticism of our media strategy and how often I’m on CNN and how often I’ve been on your show and other networks. It’s working. It’s working in spades. Because we’re so out front on this, people send us information, people want to help our cause. People contact us with information.”

Federal law requires banks to file a Suspicious Activity Report on any unusual transactions over $10,000. Experts say the information Avenatti published could have come from an SAR filed by Cohen’s bank to Treasury.

“This has the appearance of a leak,” said Daniel P. Stipano, former deputy chief counsel in the Treasury’s Office of the Comptroller of the Currency. “It shouldn’t happen, but things leak.”

It is not uncommon for journalists, lawyers and others in the public eye to receive unauthorized leaks of sensitive information, and there is nothing improper in receiving such information. Stipano said hundreds, if not thousands, of officials in law enforcement and government have access to a database of SARs.

Banks, casinos, and other entities file SARs with the Treasury Department’s Financial Crimes Enforcement Network (FinCEN) to detect for money laundering, terror financing, and other illegal behavior. FinCEN officials often scan and then aggregate the records so they can be accessed at a later date. They can be requested by law enforcement, bank regulators and intelligence agencies as part of investigations.

Among other things, banks are required to file SARs if the transaction “has no business or apparent lawful purpose or is not the type of transaction that the particular customer would normally be expected to engage in, and the bank knows of no reasonable explanation for the transaction after examining the available facts, including the background and possible purpose of the transaction.”

A spokesman for First Republic, Cohen’s bank, declined to comment.

Treasury Inspector General Eric Thorson is a George W. Bush nominee who has served in the role since 2008.

The Washington Post’s Damian Paletta contributed to this report.