The US Department of Justice (DOJ) is reportedly investigating a $372 million hack on cryptocurrency exchange FTX that occurred as the company filed for bankruptcy on November 11.

According to blockchain analytics unit, $663 million in various cryptocurrencies belonging to FTX was suspiciously on the move, with $180 million confirmed as FTX moving funds into cold storage and the remaining $477 million allegedly being quickly swapped into ether and stablecoin DAI by the hackers.

FTX CEO John Jay Ray III confirmed the hack and said the company was in contact with law enforcement.

The DOJ’s investigation is separate from the existing fraud cases against former FTX CEO Sam Bankman-Fried, who is facing an eight-count federal indictment including wire and securities fraud charges and is out on bail in California.

Bankman-Fried has suggested that the hacker could be someone from within FTX or someone who installed malware on a former employee’s computer.

Former FTX and Alameda executives Gary Wang and Caroline Ellison have both pleaded guilty to federal criminal charges and are cooperating with authorities in further investigations.