Responding to questions about the closure of Tokyo-based Mt.Gox, Japan’s Senior Vice Finance Minister Jiro Aichi told reporters that international collaboration would be necessary to regulate the currency. Aichi added that Bitcoin does not fall under his agency’s jurisdiction, as it does not involve coins or notes issued by the Bank of Japan. Under that definition, he noted “At the very least, we can say bitcoin is not a currency.”

Aichi’s statement has been interpreted by some as an indication that the Japanese government has little authority to regulate Bitcoin or other virtual currencies. Earlier today, Federal Reserve chairwoman Janet Yellen made similar statements in front of the U.S. Senate’s Banking Subcommittee, noting that the central bank has no jurisdiction over Bitcoin.

It’s not clear what shape such regulatory collaborations would take, although current international finance laws could provide some precedents. In December of last year, Bank of Japan governor Haruhiko Kuroda noted that the central bank was “researching” the Bitcoin issue, but no official statements have been released on the topic since.

The situation at Mt.Gox also caught the attention of the Japan’s Chief Cabinet Secretary, Yoshihide Suga, who announced yesterday that the country’s Financial Services Authority and National Police Agency were investigating Mt.Gox, and would “take action” if necessary.