The U.S. Attorney's Office in D.C. is now working with the FBI to "assess" accusations of election impropriety leveled against Mayor Vince Gray by a former mayoral candidate who was hired and then fired by the Gray administration.

"The U.S. Attorney’s Office and the FBI are aware of allegations, including information appearing in the media, involving the 2010 mayoral race in the District of Columbia," a statement from the U.S. Attorney's office said. " The U.S. Attorney’s Office takes these concerns seriously and is working with the FBI to assess the matter."

A law enforcement source made clear to The Washington Examiner that a full investigation was not underway. Officials, the source said, are determining whether accusations made by Sulaimon Brown are worth pursuing.

Brown claims that members of the Gray for Mayor campaign passed him envelopes stuffed with cash so he could remain on the campaign trail and attack then-Mayor Adrian Fenty. He also says Gray offered him a job if he won.

Gray did win the election and within a month of his being sworn in, Brown landed a $110,000-a-year job with the administration. He was fired weeks later when media reports surfaced about issues in Brown's past.