The U.S. Attorney's Office is considering prosecuting Kirkpatrick under the Racketeer Influenced and Corrupt Organizations statute, The Detroit News reported Wednesday.
A RICO case, traditionally used against mobsters, allows prosecution of past crimes that otherwise might fall under a statute of limitations.
Kilpatrick and his father, Bernard, are the biggest potential targets for the FBI and U.S. Attorney's Office, which have spent six years investigating City Hall corruption.
The FBI has been investigating whether contractors soliciting city work while Kwame Kilpatrick was mayor were pressured to hire his father as a consultant. Bernard Kilpatrick established a consulting firm around the time his son was elected.
Documents subpoenaed from water and sewerage contractors with close ties to the Kilpatricks and city contractor Bobby Ferguson are expected to play a key role. Ferguson already is facing eight federal counts involving a bid-rigging scheme.
Kwame Kilpatrick is serving a year and half to five years in federal prison for violating probation.