Sen. Marco Rubio, R-Fla., whose personal finance have increasingly drawn scrutiny from some of his Republican White House rivals, released previously secret records that appear to show his use of a Florida Republican Party credit card for personal expenses.

The statements, released on Saturday, showed that during a 22-month period in 2005 and 2006, Rubio charged more than $22,000 in expenses to the card, the Washington Post reported. The account in question also incurred more than $1,700 in delinquency and late fees over a four-year period while Rubio served in the Florida legislature, the newspaper detailed.

The senator has admitted that he used the American Express card for both personal and business expenses but insisted that he paid for the personal charges himself, and that the Florida GOP covered only business-related political costs, CNN noted. His campaign said that Rubio made eight personal charges, totaling $7,243.74, during the 22 months.

"Marco paid his personal charges directly to American Express," the campaign told Reuters in a statement. "The Republican Party of Florida did not pay for any of Marco's personal expenses. Further, taxpayer funds were not used for any political or personal charges on the card."

At one point, Rubio's credit card spending was the subject of an investigation by the Florida Ethics Commission, which subsequently dismissed a citizen complaint against him, the Washington Post detailed. The senator apparently repaid the Florida GOP for six airline tickets that he had double-billed to the party and the state government, and auditors were also satisfied with documentation he provided regarding other expenses they had challenged.

That, however, did not keep his Republican rival Donald Trump from raising further questions about Rubio's finances, Fox News noted.

"All you have to do is look at his credit card. I mean, he is a disaster with his credit cards," the billionaire real-estate tycoon charged. "And I'll tell you what: I love Florida. I'm in Florida all the time, and for years I've been hearing that his credit cards are a disaster."