President Donald Trump said Monday he will ask the Justice Department to investigate a recent mail ballot error in Maryland, pushing unsubstantiated claims that it was the result of fraud.

Maryland election officials are reissuing around a half-million mail ballots after they said Friday that a vendor issue led to some voters’ receiving primary ballots for the wrong party. Since election officials cannot determine who received the wrong ballot, the state is sending all potentially affected voters new ballots.

Trump said Friday on Truth Social: “In Maryland, they sent out 500,000 Illegal Mail In Ballots, and they got caught! So now, they’re going to send out 500,000 more Mail In Ballots, but nobody knows what’s happening with the first 500,000 they sent.”

The State Board of Elections had previously said that the initial ballots will be sequestered and voided and that only the replacement ballots will be cast and counted.

“There is no risk of duplicate voting as a result of this issue. Election officials have safeguards in place to ensure that only one ballot can be accepted per voter. Every return envelope/oath has a unique identifier to ensure that a voter can only vote one ballot. SBE has implemented additional safeguards to ensure only the correct ballot is counted for each voter,” the board said in a release Monday.

The error was made by a printing company, state election officials said, which will be paying for the reissued ballots. Maryland’s primary is set to take place June 23.

“It bears repeating that no fake OR illegal mail-in ballots were distributed,” Maryland’s top election official, Jared DeMarinis, said in a post on X Monday evening. “The wording in President Trump’s continued posts about Maryland’s elections creates an environment of misinformation on a voting right. Mail-in voting is not a partisan issue. Mail-in voting is legal.”

He also urged voters to trust the State Board of Elections’ website on the matter.

The call for a Justice Department investigation is Trump’s latest attack on mail balloting, which has long been at the center of his false claims of election fraud. An executive order Trump signed this year was geared toward restricting mail voting.

In his Truth Social post, Trump also singled out Democratic Gov. Wes Moore as “corrupt.”

In a statement, Moore spokesman Ammar Moussa called the president’s statement “false and irresponsible.”

“Marylanders should look to the State Board of Elections for accurate information — not social media misinformation designed to undermine confidence in our elections,” Moussa said.

The Justice Department did not respond to a request for comment.