John McCain’s campaign says it will review donations brought in by a prominent Florida businessman following disclosures that his business partner, a foreign national, also may have engaged in fundraising.

A McCain spokesman says the campaign is looking into hundreds of thousands of dollars in contributions to make sure that they are appropriate.

The campaign is sending a letter spelling out legal requirements to all donors who sent their contributions through Harry Sargeant III, the finance chairman of the Florida Republican Party.

It’s illegal for foreigners to contribute their own money to U.S. campaigns.