Tampa real estate developer Timothy F. Mobley admitted that he and another man had illegally reimbursed employees for contributions to Buchanan, according to a report from the Tampa Bay Times.

Buchanan's campaign, in a statement issued to the Times, said that he was "totally unaware" of any illegal activity and would "disgorge" the contributions.

Buchanan is also the finance chairman of the NRCC, meaning he engaged in heavy fundraising for the committee. And Mobley contributed to the NRCC during the period of time that the FBI looked into; he donated $500 in 2008 and $5,000 in 2009.

When asked whether the NRCC would be returning those funds, spokeswoman Andrea Bozek said no.

It's unclear whether these contributions were donated through any illegal means, however.