LANSING (AP) — The campaign manager for Democratic gubernatorial candidate Gretchen Whitmer resigned Thursday, a day after Whitmer said she received a credible report that he had engaged in “inappropriate behavior” in the workplace several years ago.

Keenan Pontoni joined Whitmer’s campaign in August. He was her second campaign manager and took the job after leading Democrat John Ossoff’s unsuccessful campaign in a special election for Georgia’s 6th Congressional District.

Whitmer, who is considered the front-runner for the Democratic nomination, issued a short statement announcing Pontoni’s departure.

“Yesterday, I received a credible report that a number of years ago, my campaign manager engaged in inappropriate behavior with people in the workplace and for that reason I have asked for and received his resignation effective immediately,” she said, declining to elaborate.