JEFFERSON CITY, Mo. -- A mysterious political-action committee that gave nearly $2 million to Missouri's Republican gubernatorial candidate Eric Greitens remains shrouded in secrecy after a recent Federal Election Commission report revealed little about its sole donor.

The report filed Friday showed super PAC SEALs for Truth is funded by American Policy Coalition Inc. -- another mystery group.

The committee did not respond to requests for comment submitted Monday by The Associated Press.

The website americanpolicycoalition.com shows a logo and no other information.

The super PAC has fallen under scrutiny for not disclosing the people behind the money it has funneled into this year's gubernatorial election between Greitens and Democratic Attorney General Chris Koster.

SEALs for Truth avoided reporting its donors before a contentious, four-way Republican primary Greitens won in August through a procedural quirk, leaving voters in the dark about the sources behind the donation.

Missouri law requires political donations of more than $5,000 to be reported online within 48 hours.

Federal law also requires PACs to disclose who cuts them checks, such as American Policy Coalition Inc.

But committees don't need to provide details beyond that to shed light on what interests are seeking to influence politics.

The more than $1.9 million contribution to Greitens' campaign in July broke records at the time as the biggest single donation in Missouri history before being overshadowed by multimillion-dollar checks to the GOP candidate from the Republican Governors Association.

The group gave Greitens $2.5 million Monday and last week cut two checks for $4 million and $1 million to support Greitens' campaign.

Greitens' campaign manager Austin Chambers said in an email the candidate was not available to comment Monday.

Chambers did not directly answer questions about SEALs for Truth and American Policy Coalition Inc. but stressed the campaign has received support in Missouri and across the country.

During a question-and-answer session with Missouri Farm Bureau members in August, Greitens responded to a member question about the donation by describing the committee as an example of "SEALs around this country who have stepped forward to support me."

"I come from a world where when people say that they're going to have your back, they have your back," Greitens said during the event.

"And the SEALs got together -- SEALs and Naval Special Warfare, also SWCCs, Special Warfare Combatant-Craft Crewmen -- they got together and said, 'We're going to support Eric,'" Greitens added.

Koster spokesman David Turner said Saturday that Greitens is "running a campaign with no regard for ethics or integrity."

Turner criticized the Republican's frequent pledge to fight corruption in Jefferson City as "a complete and utter joke."