Japan finance minister: Japan has not yet decided its stance on bitcoin

Some of Bitcoin enthusiast Mike Caldwell's coins and paper vouchers, often called "paper wallets", are pictured in this photo illustration taken in Sandy, Utah on January 31, 2014. REUTERS/Jim Urquhart/Files

TOKYO (Reuters) - Japan’s Finance Minister Taro Aso said on Friday that Tokyo has not yet determined its stance on the bitcoin virtual currency and that related government agencies will assess the situation.

His comments came after Tokyo-based Mt. Gox, once the world’s biggest exchange for the bitcoin crypto-currency, went blank on Tuesday after weeks of turmoil. The Mt. Gox exchange suspended withdrawals on February 7 following a series of cyber attacks, leaving customers unable to recover their funds.

Manhattan U.S. Attorney Preet Bharara has sent subpoenas to Mt. Gox, other bitcoin exchanges and businesses that deal in bitcoins to seek information on how they handled recent cyber attacks, a source familiar with the probe said. A spokesman for Bharara declined to comment.

Mt. Gox is under investigation by U.S. federal law enforcement, according to a second source familiar with the case, while a third said the U.S. Federal Bureau of Investigation was monitoring the situation.

Reporting by Tetsushi Kajimoto; Writing by Dominic Lau; Editing by Edmund Klamann