WASHINGTON (AP) — Three former executives of a Hawaii-based defense contractor have been indicted on charges of funneling more than $200,000 in illegal donations to aid the reelection campaign of Republican Sen. Susan Collins of Maine.

Former Navatek CEO Martin Kao and two others were indicted Thursday on charges of using company credit cards, a shell company and individual shell donors to make illegal contributions.

Federal contractors are prohibited from making campaign contributions beyond limits for individuals.

The indictment did not mention Collins by name and did not cite any violations by her campaign.

"As is clear in the indictment, there are no allegations of wrongdoing by the Collins for Senator campaign. As stated previously, the campaign had absolutely no knowledge of any of the allegations against Mr. Kao or his associates until a search warrant was reported in the press," her campaign said in a statement.

Kao and the other two defendants are charged with conspiracy to defraud the United States and making government contractor contributions. They will make their initial court appearances at a later date.

Kao and his attorney, along with the other two defendants, did not immediately return emails seeking comment.

He is no longer part of the marine engineering company, which changed its name to Martin Defense Group in 2020.

In August 2019, Collins announced Navatek received a defense contract worth $8 million for advanced hull planning research from its office in Portland, Maine.

The largest contribution was $150,000 provided to a super PAC through the Society of Young Women Scientists and Engineers LLC, which was created with Kao's wife as the registered agent, prosecutors said.

The straw donations from individuals to the Collins' campaign totaled more than $60,000 out of about $30 million raised by her campaign.

The illegal individual contributions were donated to help rebuild a school that burned in Frenchville, Maine, Collins' campaign said.