RIVERSIDE, Calif. (AP) — A California sheriff running for governor has seized more than half a million ballots cast in a November special election from county election officials, saying he's investigating a ballot count discrepancy.

County elections officials have disputed the claims by Riverside County Sheriff Chad Bianco, a Republican. California Attorney General Rob Bonta, a Democrat, called Bianco's move unprecedented and says it is designed to sow distrust in elections.

Bianco held a news conference Friday saying his office had launched the investigation after receiving a complaint from a local citizens group about the ballot count from a November 2025 special election on redistricting.

In the special election, voters approved a measure to redraw congressional district lines to favor Democrats in the upcoming midterm election. The measure passed in the county by a margin of more than 80,000 votes.

Bianco seized ballots in Riverside County, the inland California county of 2.5 million people where he has twice been elected sheriff. He called the effort "a fact-finding mission."

“This investigation is simple: Physically count the ballots and compare that result with the total votes reported,” he said Friday.

Bianco is one of two prominent Republicans running for governor in a crowded June primary that includes more than half a dozen Democrats. California runs a top-two primary system that puts all candidates on the same ballot, regardless of party, and sends the two candidates who get the most voters onto the November general election.

Leading California Democrats are worried that their party has so many candidates, they risk splitting the vote and sending Bianco and Steve Hilton, another top Republican, onto the general election. That would be a stunning outcome in the heavily Democratic state.

Bianco said the investigation had “absolutely nothing to do” with his campaign for governor.

“I have a duty to investigate alleged crime in Riverside County,” he said.

The effort came as President Donald Trump has repeatedly disputed the results of the 2020 election, citing unsubstantiated instances of fraud. His administration recently seized ballots and other documents from an election office in Georgia. Some Republicans have mirrored Trump's rhetoric on voting in their states.

Bonta has repeatedly sent letters to Bianco’s office over the last two months saying his staff is not qualified to conduct a recount. In one of the letters, Bonta wrote that the ballot seizure was “unacceptable” and “sets a dangerous precedent and will only sow distrust in our elections.”

The letters said Bianco seized nearly 1,000 boxes of ballots and elections materials from the county's elections office with a warrant in February. At issue, Bianco said, is a discrepancy a citizen group reported between the handwritten ballot intake logs and the number of votes reported to the state.

Bianco said the alleged discrepancy amounted to about 45,800 votes — a difference elections officials have refuted at county meetings, saying the machine count and the final count submitted to the state differed by about 100 votes. They argue the handwritten rolls, which were not relied on to check the count, were being kept by temporary elections workers who had worked long days and may have made mistakes.

Bianco said Friday that the count had started and stopped, but would now resume under the supervision of a special master appointed by a judge.