PHILADELPHIA — Disgraced ex-Detroit mayor Kwame Kilpatrick has been moved from a federal prison in Oklahoma to a federal detention center in Philadelphia.

The Detroit News reports that the 47-year-old Kilpatrick was transferred Monday. Kilpatrick was sentenced in 2013 to 28 years in prison for extortion, bribery, conspiracy and other crimes during his years in office.

He had been housed at the Federal Correction Institute at El Reno, located about 30 miles (48 kilometers) west of Oklahoma City. Kilpatrick's release date is Aug. 1, 2037.

The Bureau of Prisons website says the Philadelphia detention center houses nearly 1,040 inmates. No reason was listed on the website for Kilpatrick's transfer. The Associated Press left messages Tuesday seeking comment from the Bureau of Prisons.

Kilpatrick first was elected mayor in 2001. He resigned in 2008 following a text-messaging sex scandal involving his chief of staff. He also was charged with lying during a civil trial and jailed.