The California Supreme Court handed down an order Wednesday temporarily halting an election fraud investigation led by Riverside County Sheriff Chad Bianco, whose office has seized more than 650,000 ballots from county election officials.

The ballots retrieved by the Republican sheriff’s office were cast in the state’s special election on redistricting in the fall. Bianco is running as a California GOP gubernatorial candidate and is neck-and-neck in the polls with fellow Republican Steve Hilton, whom President Donald Trump recently endorsed.