A mid-Missouri county collector has resigned after suspicious activity was found in the county's checking account.

Callaway County officials say collector Pam Oestreich resigned suddenly Thursday and the collector's office is closed until further notice.

Prosecuting attorney Chris Wilson said in a news release that the FBI has been contacted as part of the investigation into county's checking account.

Oestreich resigned after meeting with county officials. She was serving her fourth term in office.

The county clerk currently is overseeing tax records from the collector's office. The county clerk will appoint someone to audit the records.