Japan authorities looking into closure of Mt. Gox bitcoin exchange

Japanese authorities are looking into the abrupt closure of Mt. Gox, the top government spokesman said on Wednesday in Tokyo's first official reaction to the turmoil at what was the world's biggest exchange for bitcoin virtual currency.

"At this stage the relevant financial authorities, the police, the Finance Ministry and others are gathering information on the case," Chief Cabinet Secretary Yoshihide Suga told a regular news conference when asked about Tuesday's shutdown of the Tokyo-based exchange.

Speaking shortly after The Wall Street Journal reported that Mt. Gox had received a subpoena from federal prosecutors in New York, Suga declined further comment.

Japan's Financial Services Agency and Finance Ministry told Reuters on Tuesday that they do not have jurisdiction over Mt. Gox after the exchange's website went down and efforts to reach company officials failed. The Bank of Japan said it had nothing to add to a comment by Governor Haruhiko Kuroda that bitcoin was "very interested" in bitcoin.

Mt. Gox later posted a statement on its site saying it had halted "all transactions for the time being in order to protect the site and our users."

Mt. Gox CEO Mark Karpeles told Reuters in an email: "We should have an official announcement ready soon-ish. We are currently at a turning point for the business. I can't tell much more for now as this also involves other parties." He did not elaborate on the details or give his location.

(Reporting by Kazuhiko Tamaki; Writing by William Mallard; Editing by Dominic Lau)