The announcement came Monday from U.S. Attorney Barbara McQuade.
The investigation, which began three years ago, resulted in the convictions of five people, including Wayne County's Chief Information Officer and an Assistant Wayne County Executive who served as the Director of HealthChoice of Michigan. She says the federal government won't seek additional charges in connection with the investigation.
"I would like to thank and commend the officials and staff of the Wayne County Executive and the Wayne County Corporation Counsel for their cooperation during this investigation," McQuade added in a statement. "Their assistance and openness allowed federal investigators to carefully review and assess a number of complex issues regarding the operation of county government."
The investigation had dogged Ficano's administration, contributing to his re-election loss in the August primary. The FBI probe followed an investigation of Detroit City Hall that netted dozens of convictions and sent former Mayor Kwame Kilpatrick to prison.
Ficano has denied any wrongdoing.
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