It’s possible that Ted Cruz violated federal election rules during his 2012 campaign for Senate, when he reportedly failed to disclose hundreds of thousands of dollars in loans from Wall Street banking giants Citibank and Goldman Sachs.

A campaign spokeswoman for the Senator from Texas, who is leading polls in Iowa among Republican presidential candidates, confirmed to multiple news outlets on Wednesday that Cruz did not disclose personal loans from the banks during his Senate run.

The New York Times was the first to report that financial disclosures Cruz later filed with the Senate revealed the pair of loans from Citibank C and Goldman Sachs GS , each valued between $250,000 and $500,000.

The loan from Citibank was repaid in 2012, while the loan from Goldman Sachs, where Cruz’s wife Heidi is a managing director, still has between $50,000 and $100,000 outstanding.

Cruz did eventually list the loans in a financial disclosure during his time in the Senate. But he may have violated Federal Election Commission rules that require candidates to disclose the sources of any money borrowed to finance a campaign. The Times notes that there does not appear to be any evidence that Cruz received special treatment from the lenders, but other politicians in the past have been investigated and fined by the FEC.

Cruz campaign spokeswoman Catherine Frazier told the Times and CNN that the failure to disclose the loans during the senatorial campaign was “inadvertent” and noted that the loans have since been disclosed in various filings. “It’s a matter of semantics in terms of listing that that was a loan and we’re asking the FEC what we need to do to update it, if anything,” Frazier told CNN.

As the Times also notes, the discovery of the Citibank and Goldman loans somewhat muddies the narrative Cruz has often repeated regarding his surprising, Tea Party-backed Senate win. Cruz, who has often criticized the close ties between Wall Street and politicians, previously said that he and his wife liquidated their assets to fund his 2012 campaign. Frazier told the Times that the couple did use their own stocks and savings to finance the campaign, but the Goldman loan was also used.

Fortune has reached out the Cruz campaign and will update this story if they respond.