The Republican senator, who is campaigning to retain her seat ahead of November's US midterm elections, rejected the claims after ProPublica reported that the FBI had looked into the matter. She said the allegations were recycled from 2020 and had already been rejected by the Department of Justice, the FBI and the Federal Election Commission.

"The allegations are completely false," Collins said.

A denial and an ethics complaint

Her response followed an ethics complaint filed last week by a Maine attorney. Collins said an inquiry was not up to her and dismissed the complaint as the work of "partisan Democrats" and Valerie Adams, a lawyer in Maine "who lost her election" - Adams lost a June primary for district attorney.

• •The complaint came as Collins campaigns to keep her seat before November's midterms.

What Kao claimed

According to ProPublica's September report, Martin Kao, former president and chief executive of the defense contractor Navatek, told FBI agents and prosecutors that his company won millions in federal funding by bankrolling politicians, with Collins his most important patron. Kao is serving 87 months in prison for fraud and campaign finance crimes.

• •Kao claimed the head of Collins's super PAC asked him for $500,000 in 2019.
• •He said he sent $150,000 through a shell company, after which Collins's office promised to secure $32m in naval contracts.
• •ProPublica reported the Senate allocated at least $10m that year based on Navatek's proposals, though it did not report that the full $32m was awarded; Collins says she backed the funding only because the University of Maine asked.
• •ProPublica said it reviewed FBI evidence and thousands of pages of legal records and interviewed dozens of people, independently corroborating much of Kao's account.

Collins's response on Navatek

Collins said the University of Maine, not Navatek, asked her to back a research grant, and that she had never heard of Navatek. She called Kao "a crook" whom neither she nor the university knew about. She also pointed to a photo of Kao meeting her and others in her office many months before he made any contribution.

"He spun this story up again in the hopes that the judge would be lenient, or the prosecutor would be," she said.

Among the emails cited by ProPublica, super PAC chair Scott Reed replied "Very smart" to Kao's shell company plan, and another email asked for Kao's phone number so Collins could thank him.

Where the investigation stands

ProPublica reported that FBI agents sought a broader bribery investigation in 2024, which collapsed after Donald Trump returned to office and purged the bureau's public corruption teams. No one in Collins's orbit was charged; Kao declined to be interviewed, and Reed denied discussing Kao or Navatek with Collins or her staff.

Collins defended her handling of the original complaints against her: "I was never even interviewed because there was no evidence for it," she said.