A federal investigation into California’s election process has opened after President Donald Trump made unsubstantiated claims of widespread fraud following the state’s June 2 primary, where vote counting is still ongoing.

The U.S. attorney’s office in Los Angeles confirmed Friday that it had launched “multiple election fraud investigations” regarding California’s elections and had dispatched a prosecutor to the county’s vote-counting center. The state’s ballot processing system has long been criticized by some conservatives for its extended counting timelines.

The announcement came just one day after Trump made baseless allegations of mass fraud linked to the continuing tabulation of votes in the most populous U.S. state, which is home to more than 23 million registered voters. Election observers have warned that such claims, made before final results are certified, risk fueling misinformation and public distrust.

Late-counted Democratic-leaning mail ballots have been steadily narrowing the margins for candidates backed by Trump in key races, including the contests for governor and Los Angeles mayor.

The developments were confirmed by U.S. Attorney Bill Essayli, Trump’s appointee as the top federal prosecutor in Los Angeles, and included a visit to Los Angeles County’s ballot tabulation center.

Newsweek has contacted the White House for comment via email outside of regular working hours.

Trump added to his allegations on Friday during a roundtable discussion in Chippewa Falls, Wisconsin, where he suggested, without evidence, that Democrats were manipulating the vote count.

“You look at what’s happening—it’s getting tighter and tighter and tighter,” Trump said. “And the people who were supposed to win, bad things are happening. It’s a crooked state.”

Later the same day, speaking to reporters at the White House, he doubled down on his claims, saying that election officials had uncovered suspicious ballots during the counting process. Trump said election officials in California had “found a lot of mail-in ballots last night, shockingly”.

In the days following the primary, Trump also issued a series of posts on Truth Social, repeatedly alleging fraud and irregularities in California’s vote count. His messages focused heavily on mail-in ballots and the pace of tabulation in the state.