CONCORD, N.H. (AP) — U.S. Senate candidate Corky Messner said a request for a criminal investigation into his charitable foundation in Colorado was withdrawn this week after the foundation’s attorney threatened to sue the complainants for defamation.

Messner, a Republican who is challenging U.S. Sen. Jeanne Shaheen, moved to New Hampshire in 2018 from Colorado, where his law firm created a foundation in 2009 to help underprivileged students.

In August, six prominent Colorado residents, including two former state Supreme Court justices, filed a complaint to the Colorado attorney general and secretary of state accusing the Messner Foundation of swindling buyers of raffle tickets to fund scholarships, in part because the foundation provided just one scholarship in its first decade of existence. Several of the complainants have ties to the Democratic Party, including a former state lawmaker and a former U.S. Senate candidate.

Messner’s campaign released a Monday letter from the complainants’ lawyer saying they agreed to withdraw the complaint, along with the withdrawal notice that it was filing with the state. The foundation on Friday had threatened to sue.

Two of the complainants did not respond to a phone message Wednesday, and the group's attorney did not respond to emails or a phone message. The Colorado secretary of state's office and attorney general's office declined to comment.

Messner argued that the foundation didn’t solicit public funding until 2015 and awarded its first scholarship the following year. In an interview Wednesday, he said an auditor retained by the foundation’s attorney found no wrongdoing.

“Neither the foundation nor I have done anything wrong,” he said in an interview Wednesday. “The foundation is small, but it has helped a couple of young people, and that’s the intent of the foundation. Those allegations were purely a political hit job.”

Shaheen campaign manager Harrell Kirstein referred to a Washington Post article that found that the foundation gave more money in its first decade to a private school attended by Messner’s sons than it did its first scholarship recipient.

“As a result, Messner received ‘four Pinocchios’ from the Washington Post, also known as a ‘whopper,’ and Messner has yet to explain or apologize to Coloradans and Granite Staters for the way that he conducted this 'charity,'” Kirstein said in a statement.

The 2014 donation to Colorado Academy was funded by Messner's law firm, not raffle ticket sales, though the foundation at the time advertised itself as helping underprivileged students.