But Greitens' big numbers contain what has become a familiar caveat: almost two-thirds of his money was donated by wealthy contributors who don't reside in Missouri, but live in California and other states. That has spurred critics to question in the past where his loyalty would lie as governor.

Missourians will choose their party nominees in the Aug. 2 primaries, with the winners facing off in the Nov. 8 general election.

The four-way race for the GOP nomination has been contentious, and has included a bitter personal argument during a phone conversation between Greitens and Brunner that Brunner secretly recorded and which was later aired publicly.

Brunner's records, eye-popping at first, show he raised more than $682,000 in donations during the three-month period, and is currently sitting on more than $3.6 million.

But the details in the records bear out what observers have been expecting for awhile: Brunner, who also has never held office, is starting to sift his fortune into his campaign, as he did in his failed attempt to win the GOP nomination to the U.S. Senate in 2012. He lost that primary to U.S. Rep. Todd Akin, who went on to lose to incumbent Sen. Claire McCaskill, D-Mo.