An accountant for former Trump campaign chairman Paul Manafort admitted at Manafort’s tax- and bank-fraud trial Friday that she filed tax returns she thought contained false information and that she may have committed a crime in doing so.

Accountant Cindy LaPorta said she had a sense that what Manafort and aide Rick Gates told her about funds being transferred into their international political consulting business wasn’t accurate.

“I prepared the tax returns and communicated with banks based on information that Mr. Gates and Mr. Manafort provided to me that I didn’t believe,” said LaPorta, the first witness at the trial to testify under a grant of immunity.

The admission is the first time a witness has acknowledged knowing involvement in potential wrongdoing during Manafort’s trial, where the longtime lobbyist is fighting charges brought by special counsel Robert Mueller. LaPorta is one of five people on the Mueller’s witness list for whom the government requested immunity.