ATLANTIC CITY — An early morning altercation Sunday outside the Haven Nightclub at the Golden Nugget casino involving Atlantic City Mayor Frank Gilliam and City Councilman Jeffree Fauntleroy II is under investigation by the Atlantic County Prosecutor's Office.

According to a police source familiar with video of the incident, the men were seen leaving the club and then becoming involved in a fistfight with several people, believed to be club employees who followed them outside, about 2:30 a.m.

On Monday, Lt. Gov. Sheila Oliver, who has legislative control over Atlantic City under a state takeover entering its third year, said in a statement that "the allegations are troubling, and we understand law enforcement is looking into it. We are committed to continued progress in Atlantic City and are working to make sure that happens."

On  Monday, Fauntleroy said he and Gilliam had "tried to leave a bad situation."

"We were leaving," he said. "We actually walked out. We were going to our cars."

Fauntleroy said a reporter for the news site BreakingAC  had shown him a copy of a police communication indicating that complaints had been filed against him and Gilliam on allegations of simple assault and harassment. He said he had not otherwise been informed of any complaint or law enforcement action against him or the mayor. The men left before police were called to the scene.

Gilliam did not return messages asking for comment.

"When we go out, we're actually targets," Fauntleroy added. "Sometimes things get provoked into situations where you have to, actually … things happen."

In a statement Sunday, the Prosecutor's Office said it was aware of an incident "involving Atlantic City Mayor Frank Gilliam, Atlantic City Councilman Jeffree Fauntleroy II, and three other individuals" and had the matter under review, and declined further comment.

Atlantic City Police Sgt. Kevin Fair referred questions Monday to the Prosecutor's Office, which did not return messages.

Oliver is due in town this week for a meeting of an oversight committee and the annual gathering of the League of Municipalities.

City Council President Marty Small Sr. also declined to comment, except to say he was focused on the city's budget.

Gilliam was quoted by the Atlantic City Press early Sunday as saying "nothing happened."  Late Sunday, after it reviewed video that showed the mayor exchanging punches with another man, the Press said Gilliam acknowledged that there was a physical altercation.

The general manager of Haven did not return messages for comment, and a spokesperson for the Golden Nugget said the casino would have no comment.

In 2010, then-Councilman Gilliam was involved in an altercation on a street that resulted in the filing of complaints by Gilliam and the other man for simple assault, according to the Press.