Bitcoin exchange Mt. Gox has filed for bankruptcy in Tokyo after 850,000 bitcoins valued at about $475 million "disappeared."
"There was some weakness in the system, and the bitcoins have disappeared. I apologize for causing trouble," CEO Mark Karpeles said at a Friday press conference in Japan.
The company's website has shut down except for a Wednesday statement by Karpeles.
"As there is a lot of speculation regarding MtGox and its future, I would like to use this opportunity to reassure everyone that I am still in Japan and working very hard with the support of different parties to find a solution to our recent issues," Karpeles said then, adding that the company's staff has been ordered not to respond to any inquiries.
"I am sorry for the troubles I have caused all the people," Karpeles said Friday. He reportedly bowed to Japanese media for several minutes.
Reports estimate the Tokyo company's debts at 6.5 billion yen ($63.6 million). According to the BitcoinCharts website, Mt. Gox's bitcoins have traded between $91.50 and about $969.40 over the past 30 days, with the last trade at $135. Mt. Gox's volume over the period totaled $347.28 million.
Masako Mori, minister of Japan's Consumer Affairs Agency, said the ministry is "at a loss" for how to help in the situation.
The Deal Pipeline reported on Feb. 7 that Mt. Gox had halted customer withdrawals after an increase in activity. The company said it took action after it said it detected "unusual activity on its bitcoin wallets and performed investigations during the past weeks."