Head of Mt Gox bitcoin exchange on trial for embezzlement and loss of millions

Mark Karpelis faces up to five years in jail as Japanese authorities press charges in bankruptcy case that lost 850,000 bitcoins and $28m of user money

The 32-year-old head of failed bitcoin exchange Mt Gox pleaded not guilty on Tuesday to charges relating to the loss of hundreds of millions of dollars worth of bitcoins and cash from what was once the world's biggest exchange based in Japan.

Mt Gox, which handled around 80% of global bitcoin trades, shut down and went bankrupt in February 2014, saying that it had lost about 850,000 bitcoins - then worth around half a billion US dollars - and $28m (22m) in cash from its Japanese bank accounts. The Tokyo-based Mt. Gox blamed hackers for its lost bitcoins, pointing to a software security flaw, but subsequently said it had found 200,000 of the missing bitcoins.