A coalition of former Republican officials asked the Justice Department to immediately investigate billionaire Elon Musk’s cash awards for voters.

Musk — the world’s richest person — has thrown his financial might behind former President Donald Trump’s bid for the White House. He said last week he would hand out the million-dollar sweepstakes each day until Nov. 5 through his America PAC. Registered voters in swing states who sign the group’s petition to “support free speech & the right to bear arms” are eligible.

But those promises raise serious questions under federal law, a group of officials — which include a former deputy attorney general, a Watergate prosecutor and a former chairman of the Federal Election Commission — wrote to the Justice Department.

“We are aware of nothing like this in modern political history,” the group wrote in the letter. “We recognize that they are framed as payments for signing a petition, or for referring voters who sign. But many of the payments are restricted to registered voters, so anyone who wishes to get paid must first register.”

The Washington Post, the first to report the news, said Attorney General Merrick Garland has received the letter, but the DOJ did not say if it would investigate.

Musk initially offered smaller monetary boons for those who signed the petition and encouraged others to do so. He had offered people who refer signers $47 per referral, but later upped that offer to $100 for both those who signed and those who referred.

Those payments prompted concern from some legal experts, but also debate about their legality as some likened them to common election-time efforts. Musk’s PAC is also only encouraging swing state voters to sign a petition.

But the officials argued in the letter that the political group’s plan was merely a ploy to get people to register, which would violate the law.

“Moreover, while the usual purpose of a petition is to demonstrate public support for some proposition, America PAC’s petition does not appear to serve that purpose,” the letter says. “And, critically, America PAC has not made the names or numbers of petition signers public — so the petition provides no demonstration of public support for even that statement.”

The group went on to say that law enforcement agencies were often hesitant to “take action shortly before elections that could affect how people vote.”

“Serious questions arising under laws that directly regulate the voting process must be an exception,” the letter reads. “Otherwise, individuals may act with impunity, with consequences if any coming only long after the damage is already done.