Mt. Gox, once the world's biggest bitcoin exchange, filed for bankruptcy protection on Friday, saying it may have lost all of its investors' virtual coins due to hacking into its faulty computer system.
Chief executive Mark Karpeles, bowing in contrition and wearing a suit instead of his customary T-shirt, apologised in Japanese at a news conference for the company's collapse, blaming "a weakness in our system."
Angry investors have been seeking answers for what happened to their holdings of cash and bitcoins, an unregulated crypto-currency, on the Tokyo-based exchange. The collapse of the company has shaken the virtual currency world.
Mt. Gox deleted its website on Tuesday after freezing withdrawals earlier this month in the wake of a series of technical difficulties.
The exchange had liquid liabilities of 6.5 billion yen ($63.67m), dwarfing its total assets of 3.84 billion yen, the company said. It had 127,000 creditors in bankruptcy, just over 1,000 of whom are Japanese.
The company and Karpeles have said little in the days before the filing, which is similar to Chapter 11 bankruptcy in the United States, except that they were working with others to resolve their problems.
Karpeles told the news conference that Mt. Gox wanted to file a criminal complaint against what he said was a hacking attack, but had no specific means of doing so.