The FBI has been asking questions about embattled Atlantic City Mayor Frank Gilliam involving allegations of financial improprieties since early this year, several sources with direct knowledge told NJ Advance Media.

Two of those sources said they were interviewed on two occasions , most recently in late summer, about financial improprieties, including the mayor’s alleged mishandling of a $10,000 campaign check, despite the fact he was cleared of wrongdoing by a Superior Court judge earlier this year. The sources requested anonymity because they said they feared it would compromise any federal inquiry and because of concerns about potential reprisal.

On Monday, shortly before 8 a.m., roughly a dozen federal agents from the FBI and IRS descended on the Ohio Avenue home of the mayor to execute a search warrant. For the better part of the morning, they were seen exiting the house with at least 10 bankers boxes and a computer from the residence.

“We can confirm that our agents were executing a search warrant at the home of Mayor Frank Gilliam,” said Doreen Holder, a public affairs specialist with the FBI’s Newark office.

In March, Atlantic City councilman George Tibbitt told the Philadelphia Inquirer that he’d been interviewed by the FBI about checks intended for his campaign ending up in Gilliam’s campaign account. Last week, Tibbitt told NJ Advance Media that he was interviewed “about checks stolen from me.”

In March, a criminal complaint was filed In Superior Court about a $10,000 check to the Atlantic City Democratic Committee in Superior Court which had been deposited in Gilliam’s own campaign’s account.

The mayor said the $10,000 check was deposited into his account in error. In April, Superior Court Judge Bernard DeLury dismissed the charges saying there was not “even a scintilla of evidence” of wrongdoing in the matter, and the state dropped the case.

“I have no comment,” said Gilliam, when reached on his mobile phone by NJ Advance Media last week about the FBI interviews.

On Monday, the mayor declined to comment as he was seen leaving his house after the FBI raid.

The mayor is also facing two summonses in municipal court for simple assault and another for harassment stemming from a 2:30 a.m. brawl outside the Golden Nugget Casino’s Haven nightclub last month. The Cape May prosecutor’s office announced last week that it will not pursue charges against Gilliam, but complaints will be heard in municipal court next week.

Meanwhile, Gilliam has been facing an open revolt from his own party pending the resolution of the municipal assault charges.

Last week, the Atlantic City Democratic Committee voted 27-3 on a resolution seeking the removal of Gilliam and city councilman-at-large Jeffree Fauntleroy II to leave their positions without pay until the assault investigation is concluded.

The committee also asked Gov. Phil Murphy and Lt. Gov. Sheila Oliver to remove them from office if they did not step down.

Lt. Gov. Sheila Oliver said last week that the governor’s office would not intervene.

John Devlin, a Democratic committeeman in Atlantic City, said the Atlantic City Democratic Committee had no choice but to mount a recall effort against the mayor.

"We’re getting support from the whole community to move forward with the recall effort,” said Devlin, “Because perception is reality, and right now the perception is that Atlantic City’s corrupt: You’ve got a mayor taking $10,000 donations and beating people up. Who would invest here?”

Reporter Chris Franklin contributed to this story.

Claude Brodesser-Akner may be reached at cbrodesser@njadvancemedia.com. Follow him on Twitter @ClaudeBrodesser. Find NJ.com Politics on Facebook.