After a man wearing an FDNY jacket was seen in a photograph of pro-Trump rioters outside the Capitol last week, the FDNY has made the FBI aware of allegations that members of the department participated in the insurrection.

"The department received anonymous allegations that active or retired members were present at the events at the United States Capitol on January 6 and, as required, has provided that information to the FBI," FDNY spokesman Frank Dwyer said in a statement.

One photo published by the Daily News and Daily Mail shows a person in the mob of rioters outside the Capitol building on Wednesday wearing an FDNY Squad 252 jacket. A source also tells the News that "an active FDNY firefighter was also photographed at the scene, but was not wearing anything identifying him as a city firefighter."

Squad 252 is a Special Operations Command located in Bushwick. Dwyer told the NY Post that he could not identify the individual but said they are “believed to be retired.”

The FBI has arrested over a dozen people who were photographed in and around the Capitol during the insurrection, but no NYC residents so far. A firefighter from Sanford, Florida is under investigation and suspended with pay after a local news station identified him in a photo showing insurrectionists inside the Capitol.

On Friday, an MTA worker was suspended after he was found to have participated in the mob that broke into the Capitol building. On Thursday, Gothamist identified one of the insurrectionists inside the Capitol as New Yorker Aaron Mostofsky, the son of a Brooklyn Supreme Court judge. It appears that Mostofsky has not been arrested -- the NY Post photographed him leaving his home on Friday.

The U.S. Attorney’s Offices that have been prosecuting individuals involved in the insurrection did not immediately respond to a request for comment on Sunday.

Asked to confirm the investigation into FDNY members' alleged participation in the riot, which left five people dead including a Capitol Police officer who was killed by the mob, an FBI spokesperson declined to comment.

One Capitol Police officer told BuzzFeed that some of the rioters besieging the Capitol building flashed police badges at him, but did not say where they were from. “[One guy] pulled out his badge and he said, ‘We’re doing this for you.’ Another guy had his badge. So I was like, ‘Well, you gotta be kidding,'" the anonymous officer recalled.

On Sunday evening, NYPD spokesperson Edward Riley issued a statement saying, "The New York City Police Department is assisting Capitol Police in their request to determine whether or not any one employed as a New York City police officer was involved in the assault on our nation’s capital. There is no evidence at this time that any were. But we are reviewing footage and using all investigative methods to make a determination and assist our law enforcement colleagues."

Earlier on Sunday, before the NYPD's statement, State Senator Zellnor Myrie called on the department to at least acknowledge the attack, and "assure New Yorkers of their safety."

At a press conference on Saturday, Mayor Bill de Blasio said there were "no real and specific threats directed to New York City at this moment," but officials were "monitoring very very closely."

This story has been updated with a statement from the NYPD.

Additional reporting by Yasmeen Khan.