Alumnus and Mayor Vincent Gray is in hot water with federal investigators for allegedly running an unreported “shadow campaign” during the 2010 campaign season that included organizing and financing a get-out-the-vote operation that were kept under wraps.

The alleged shadow campaign began to put a little more cash in Gray’s campaign pockets when he was an underdog in the race against former Mayor Adrian Fenty, The Washington Post reported Thursday. The post anonymously cited former campaign staffers. D.C. Office of Campaign Finance guidelines require candidates to report all spending related to city campaigns and candidates.

They claimed former field organizer Vernon E. Hawkins organized that operation.

“Hawkins did not return calls seeking comment, and Gray said it was his understanding that Hawkins was a campaign volunteer. Gray declined to answer specific questions about the campaign allegations, citing the ongoing investigation,” The Post reported.

The story follows a federal investigation into Gray’s campaign irregularities, and a slew of charges surrounding his bid the city’s top executive seat. A federal probe dismissed an allegation by ex-candidate Sulaimon Brown that the alumnus’ staff bribed him to bash Fenty during the race in exchange for a city job.

Gray, who has been slammed with ethical inquiries into his campaign since he took office, has repeatedly denied any wrongdoing.