The publication reported Monday its review of public records and other documents found evidence Paul appears to have been paid twice for flights from Washington to his home congressional district, getting reimbursed by the House and from political and non-profit organizations he oversaw.
Paul's office denied he intentionally received multiple reimbursements for the same trips.
Evidence indicates eight flights were reimbursed twice, Roll Call said, adding it also found instances of other duplicated travel payments from 1999 to 2009, but information in those cases wasn't as complete.
The duplicated reimbursements totaled thousands of dollars.
Paul spokesman Jesse Benton acknowledged it was "possible that wholly inadvertent errors were made in a handful of instances" in which flights were reimbursed twice. However, Benton stressed to Roll Call "absolutely zero taxpayer funds were ever misused."
Benton said flights "may appear to show duplicative reimbursements because Congressman Paul's wife or a campaign staffer traveled with him. In such instances, the U.S. House would reimburse Congressman Paul's travel to D.C. for congressional business, while his campaign or political action committee would reimburse his traveling companion's ticket."
Benton declined to discuss the trips, saying the office does not have records for many of the years, then telling Roll Call it was using "stolen" credit card records for its story.
The publication said it obtained copies of credit card statements for a corporate American Express card assigned to Ron Paul & Associates Inc. that listed particulars of the flights purchased. Flight details on the American Express statements matched payment records filed with the Federal Election Commission and office expenses in quarterly congressional disbursement statements published by the House chief administrative officer.