LOS ANGELES — Los Angeles City Councilman Mark Ridley-Thomas was indicted Wednesday on federal charges of taking bribes from a former University of Southern California dean in exchange for supporting millions of dollars in L.A. County contracts with the university when he was on the county Board of Supervisors.

A federal grand jury accused Ridley-Thomas of conspiring with Marilyn Louise Flynn, then dean of USC’s School of Social Work, to steer county money to the university in return for admitting his son Sebastian into graduate school with a full-tuition scholarship and a paid professorship.

The 20-count indictment alleges that Flynn and Ridley-Thomas also concocted a scheme to funnel $100,000 from one of his campaign committees through the university to a nonprofit where his son would work.

Ridley-Thomas, 66, one of the most powerful political figures in Los Angeles, and Flynn each face charges of conspiracy, bribery, mail and wire fraud.

The criminal charges are the latest in a string of scandals that have marred USC’s reputation in recent years.

The indictment comes three years after the Los Angeles Times revealed that USC had provided a scholarship to Sebastian Ridley-Thomas and appointed him as a professor around the time that then-Supervisor Ridley-Thomas had funneled campaign money through the university that ended up in a nonprofit group run by his son. The Times reported that USC alerted federal prosecutors to the unusual arrangement following an internal investigation.

“This indictment charges a seasoned lawmaker who allegedly abused the public’s trust by taking official actions to benefit himself and his family member,” acting U.S. Attorney Tracy L. Wilkison said. “The corrupt activities alleged in the indictment were facilitated by a major university’s high-ranking administrator whose desire for funding apparently trumped notions of integrity and fair play.”

Ridley-Thomas and Flynn could not immediately be reached for comment.