Former Trump campaign chief Paul Manafort has trouble in his own house. According to court documents, one of Manafort’s former employees led an FBI agent to a storage locker filled with paperwork on Manafort’s businesses and finances. The person’s name is redacted from the filings. But he’s now at the center of a fight over evidence that could play a significant role in the government’s case against Manafort.

“People do strange things when confronted with authoritative FBI agents,” said Sol Wisenberg, a criminal defense attorney with Nelson Mullins.

This makes the second Manafort associate known to have aided the government in the sprawling investigation into foreign influence in U.S. politics. Rick Gates, Manafort’s long-time right hand, began cooperating with Special Counsel Robert Mueller’s office in February.