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.