Two of FTX founder Sam Bankman-Fried’s closest associates have pleaded guilty to fraud and agreed to co-operate with US authorities investigating the collapse of the bankrupt cryptocurrency exchange, a federal prosecutor in Manhattan said on Wednesday.

Damian Williams, the US attorney for the Southern District of New York, announced the guilty pleas and criminal charges against Caroline Ellison, former chief executive of FTX trading affiliate Alameda Research, and Zixiao “Gary” Wang, a co-founder of FTX, in a short video statement. His office had brought eight charges against Bankman-Fried last week.

The announcement from Williams came just after a plane carrying Bankman-Fried took off from the Bahamas, where he waived his right to challenge extradition to the US. He landed in New York late on Wednesday, local media reported, and is due to appear in a Manhattan court as soon as Thursday, where his bail request will be considered.

The trio of longtime friends were among the key members of a tight circle of associates who ran Bankman-Fried’s crypto empire, which included the FTX cryptocurrency exchanges and Alameda Research, the private trading firm. All three had lived together with other senior executives in a luxury apartment in Nassau’s Albany complex.