A robocall that appears to be an AI voice resembling President Joe Biden is reaching out to New Hampshire residents, advising them against voting in Tuesday’s presidential primary and saving their vote for the November general election.

Audio of the call was reviewed by CNN from the anti-robocall application Nomorobo. Their tracking data suggests a large volume of calls. It’s unclear who is behind the call.

“Republicans have been trying to push nonpartisan and Democratic voters to participate in their primary. What a bunch of malarkey,” says the digitally altered Biden voice. “We know the value of voting Democratic when our votes count. It’s important that you save your vote for the November election. We’ll need your help in electing Democrats up and down the ticket. Voting this Tuesday only enables the Republicans in their quest to elect Donald Trump again.”

The application rates the number of calls, which were first reported by NBC News, as “severe,” among its highest rating for calls.

Nomorobo CEO Aaron Foss told CNN their data showed that 76% of the robocalls targeted New Hampshire, with 12% directed at Boston and the remaining 12% covering other areas. They estimated the number of these fraudulent calls ranged from 5,000 to 25,000.

Biden’s name will not appear on the ballot in the upcoming New Hampshire primary on Tuesday over a dispute between the state and the Democratic National Committee, which voted to move the New Hampshire primary out of its traditional first-in-the nation position. As a result, there is an organized effort to write-in Biden’s name.

“This matter has already been referred to the New Hampshire Attorney General, and the campaign is actively discussing additional actions to take immediately. Spreading disinformation to suppress voting and deliberately undermine free and fair elections will not stand, and fighting back against any attempt to undermine our democracy will continue to be a top priority for this campaign,” Julie Chavez Rodriguez, Biden’s campaign manager, said in a statement.

Aaron Jacobs, a spokesperson for Write-In Biden, said in a statement, “This is deep fake disinformation designed to harm Joe Biden, suppress votes, and damage our democracy,” adding that the group remains “focused on one goal until polls close on Tuesday: encouraging Granite Staters to write-in Joe Biden.”

At the end of the call, the voice of an unknown male directs listeners to call a local New Hampshire number to be removed from future calls.

The call uses spoofing, a common practice in fraudulent robocalling which manipulates caller ID information to display a false phone number, obscuring the true identity of the caller.

The robocall shows up on caller ID as a local New Hampshire number that belongs to Kathy Sullivan, a former New Hampshire Democratic Party chair and treasurer for the Granite for America PAC. The PAC is working to encourage voters to write in Biden’s name this Tuesday.

In a phone interview, Sullivan, who is supporting Biden in the 2024 election, said she first received calls on Sunday night and spoke with the New Hampshire attorney general’s office on Monday to file a complaint over the robocall.

“It’s very apparent that there’s someone, or someones, out there who want to suppress the primary write-in vote on Tuesday, tomorrow, by sending out this robocall saying, ‘Don’t vote for Joe Biden,’ or Joe Biden saying, ‘Don’t vote on Tuesday, save your vote until November,’” said Sullivan. “It’s voter suppression by someone who wants to hurt Joe Biden.”

Sullivan said she believes her phone was listed as a way to “jam” up her phone lines.

“It’s personally annoying, but more importantly it’s just reprehensible that someone would be trying to suppress the vote by telling people not to vote on Tuesday,” she said. “That’s an interference with our democracy. It doesn’t get much worse than that.”

The campaign of Minnesota Rep. Dean Phillips, who is challenging Biden in the New Hampshire primary, found out about the call from reporter outreach last night, according to spokesperson Katie Dolan.

“Any effort to discourage voters is disgraceful and an unacceptable affront to democracy,” Dolan said in a statement. “The potential use of AI to manipulate voters is deeply disturbing.”

CNN’s Alison Main and Edward-Isaac Dovere contributed to this story.