Prosecutors have filed charges against Mark Karpeles, the former head of defunct bitcoin exchange Mt. Gox, accusing him of stealing ¥321 million ($2.7 million) of clients' money.

The French-born Karpeles, 30, was arrested last month in connection with the disappearance of hundreds of millions of dollars worth of the virtual currency.

The charges, which were filed Friday, said Karpeles embezzled the funds by transferring clients' deposits with Mt. Gox to other accounts.

The prosecutors' office was not available for comment.

The money was spent on buying computer software development rights and an expensive custom-built bed, Jiji news said, quoting sources familiar with the matter.

Karpeles was suspected of falsifying data on the outstanding balance of the exchange, at one point the world's largest hub for trading the digital currency, Japanese media reported at the time of his arrest.

Karpeles has denied the charges, telling investigators the data falsification was done for the company and he had intended to pay back the money.