Mar-a-Lago employee aids investigation into whether Trump hid documents

The identity of the cooperating witness and the extent of the information divulged remains unknown, but the person was reported as having turned over a picture of the storage room where the vast majority of the classified documents at the property had been located.

The development comes as the special counsel Jack Smith has renewed efforts to focus on whether the failure by Trump to fully comply with a subpoena last year demanding the return of any classified documents was a deliberate act of obstruction, multiple people familiar with the matter said.

But Nauta has emerged as a central player in the incomplete subpoena response, after he was seen on the surveillance footage going in and out of the storage room to collect and return boxes both before and after the subpoena was issued to Trump in May of last year.

Nauta himself has turned into a dead-end for investigators when, last fall, the justice department threatened to charge him with obstruction or making false statements to the FBI after he gave differing accounts to investigators in an effort to scare him into cooperation.

Some people inside the justice department believe that threatening Nauta with prosecution so early on in the investigation was a mistake, and that they could have taken a lighter approach that could have led to answers for issues that have since cropped up, one of the people said.

After losing Nauta, investigators have turned to other witnesses who could shed light on his role. In recent interviews, they have asked whether Nauta removed boxes containing classified documents when he was in the storage room at the time of the subpoena, and where he went with them.