Former Detroit mayor Kwame Kilpatrick, shown here at his sentencing in May, is facing new charges related to fraud and taxes. ((Paul Sancya/Associated Press) )

Imprisoned former Detroit Mayor Kwame Kilpatrick is in trouble with the law -- again.

Kilpatrick was indicted Wednesday on federal fraud and tax charges.

Federal prosecutors said the alleged scheme is related to the Kilpatrick Civic Fund, which is a tax-exempt fund that was supposed to pay for voter education.

Instead, Kilpatrick is accused of using it as a slush fund to take cash payments for himself, friends and relatives.

Prosecutors accuse him of failing to report at least $640,000 in taxable income between 2003 and 2008, which includes money and private jet flights.

Kilpatrick is already in prison for up to five years for violating probation stemming from his conviction for lying under oath about an affair.