The Federal Election Commission has sent a letter to Ted Cruz demanding further explanation of Goldman Sachs’ loan to his 2012 Senate campaign.

Cruz and his wife, Heidi, took out a low-interest loan from Goldman Sachs, and another from Citibank, without the required disclosure to the Federal Election Commission, The New York Times reported in mid-January. The next day, Cruz’s team sent a letter to the FEC clarifying that the loan, which had been marked as personal funds, should have been reported as from bank loans. The FEC’s response, dated Tuesday, asks Cruz’s staff to further amend their reports to include more details and file an additional document with the exact terms of the loan.

In the runup to the Iowa caucuses, Cruz was called out for the disclosure issue, as well as the hypocrisy of slamming Goldman Sachs while simultaneously taking their loan. Heidi Cruz is on unpaid leave from the investment bank, where she works as a managing direction in their Houston office.

The Cruz team did not immediately respond to a request for comment.

—Tim Mak