Fresh warrant resets clock for grilling MtGox CEO over missing bitcoins

The arrest of MtGox boss Mark Karpeles has begun to shed light on the defunct bitcoin exchange after hundreds of millions of dollars in virtual currency vanished from its digital vaults last year.

But as details of a lengthy investigation by Japanese police trickle out, at least one crucial question remains unanswered: where is the money?

On Friday authorities issued a fresh arrest warrant for Frenchman Karpeles over claims he stole several million dollars from clients, including about US$48,000 allegedly spent on a bed. Karpeles, 30, who has reportedly denied the allegations, was initially taken into custody earlier this month and has been held without formal charges for three weeks, as allowed under Japanese law. A fresh warrant resets the clock on how long police can hold and grill him over Tokyo-based MtGox's missing bitcoins.

So far, police have accused Karpeles of manipulating data and stealing sums that amount to just a fraction of the 850,000 coins - worth around US$480 million at the time, or US$387 million at current exchange rates - that disappeared last year.

MtGox, which once handled around 80 per cent of all bitcoin transactions, filed for bankruptcy protection soon after the cyber-money went missing, leaving a trail of angry investors.

The company initially said there was a bug in the software underpinning bitcoins that allowed hackers to pilfer them.