The head of the Bank of Japan on Tuesday cast doubt on Bitcoin's future, saying the scandal-plagued digital unit "cannot be a currency" unless it proves its reliability.
The US tax authority on Tuesday ruled that Bitcoin will be taxed as property, like stocks or real estate, rather than as a basic currency like the dollar.
Failed Bitcoin exchange MtGox says it has found 200,000 coins worth $116 million in an old "digital wallet", after it collapsed in February admitting it had lost half a billion dollars in a possible theft.
A US financial regulator warned consumers Tuesday that using the online currency Bitcoin is fraught with risks including theft by hacking and fraud.
The collapse of Japan's Mt. Gox bitcoin exchange is spilling into U.S. bankruptcy court as the company scrambles for legal cover after losing digital currency valued at $473 million.
Bitcoin exchange MtGox faced massive hacker offensives last month, coming under some 150,000 DDoS attacks per second for several days ahead of its spectacular failure, a report said Sunday.
Whether you see Bitcoin as the future of finance or a reckless gamble, the digital currency has become headline news over the past year, even as its origins remain shrouded in mystery.
A man named as being the enigmatic creator of Bitcoin on Thursday denied having a role in the virtual currency, telling reporters he was not involved.
Dorian Prentice Satoshi Nakamoto denied Thursday that he is the creator of bitcoin.
Bitcoin is not a currency but transactions involving it should be "subject to taxation", Japan's government said Friday, in a move that could pave the way for formal regulations on the troubled virtual unit.