The former Navy SEAL who ignited a controversy when he publicly claimed credit for killing Osama bin Laden is under investigation for possibly leaking official secrets, The Daily Beast has learned.

When reached for comment, Ed Buice, an NCIS public affairs officer, confirmed “The Naval Criminal Investigative Service (NCIS) is in receipt of an allegation that Mr. O’Neill may have revealed classified information to persons not authorized to receive such information. In response, NCIS has initiated an investigation to determine the merit of the allegations.”

The news that O’Neill is being investigated for potential criminal acts hasn’t been previously reported.

In previous interviews with The Daily Beast, former Special Operations officials, as well as other sources who are familiar with the raid on bin Laden’s compound, accused O’Neill of misstating key facts and wrongly taking credit for killing the world’s then-most-wanted man.

At issue is who fired the shot—or shots—that hit bin Laden in the head, splitting open his skull and almost certainly ending his life. O’Neill insists that he was the shooter. Fellow SEAL Matt Bissonnette also claims to have shot bin Laden. But others say a still-unidentified man likely fired the round that caused a lethal head wound.

It wasn’t clear to whom specifically O’Neill is alleged to have disclosed classified information, or what that information was. Bissonnette is already under investigation for revealing details about the bin Laden raid and technical aspects of Special Operations in a book, No Easy Day, which he declined to vet with military censors before publication.

O’Neill hasn’t written a book, but he has spoken with journalists about his role in the raid, and particular details about how it was conducted. O’Neill was the anonymous subject of a 2013 Esquire magazine profile. He also sat down with Fox News for a documentary that the network aired last month, built around O’Neill’s role in the operation.

Days before the documentary was set to air, O’Neill was identified on the blog SOFREP. The Washington Post then ran an interview with O’Neill before he appeared on television.

O’Neill contends that the non-disclosure agreements he signed while in the military didn’t cover aspects of the raid that he discussed with journalists, according to people familiar with the matter.

A representative for O’Neill, who tours on the public speaking circuit, didn’t immediately respond to a request for comment.

The military has been trying to stop current and former special operators from discussing their secretive profession. And some members of the Special Operations community have strongly criticized Bissonnette and O’Neill as attempting to profit off the successful bin Laden raid, for which they say no one can claim sole credit.

In October, the head of Naval Special Warfare Command reminded SEALs in a letter that they had signed non-disclosure agreements and pledged not to reveal properly classified information. But some special operators have argued that Bissonnette and O’Neill are only discussing details that were already leaked to journalists by White House and military officials, including in the days after the bin Laden raid.

The leaks were so voluminous, according to a book by New York Times reporter David Sanger, that then-secretary of Defense Robert Gates told the White House that officials should “shut the fuck up” about the raid.

“In normal circumstances, the Navy would be right to pursue an investigation but there’s still no evidence that a disclosure of any type occurred,” said Joe Kasper, the chief of staff for Rep. Duncan Hunter, a California Republican and Marine reservist who knows O’Neill. “Regardless of whether you think Rob O’Neill should have identified himself or not, an investigation will need turn up credible evidence that disclosures were made—and on that front, at least so far, there’s no compelling evidence that occurred.”

Editor’s Note: This piece has been updated to include the comments of the Navy and Duncan Hunter’s office.