Community, Sport and Cultural Development Minister Coralee Oakes says Arn van Iersel will fill the post on an acting basis.
Van Iersel previously served as B.C.'s comptroller general and acting auditor general, and Oakes says he will provide strong leadership during a transition period.
Oakes says the Audit Council, which monitors the local government auditor office, recommended van Iersel's appointment.
Ruta was dumped last week just days after she complained about a possible bias by the man appointed to investigate her work.
Oakes says a review of the office's operating structure by former bureaucrat Chris Trumpy will continue.