Former cryptocurrency Mt. Gox CEO Mark Karpeles looking at 10 years in prison

TOKYO — Prosecutors on Wednesday proposed a 10-year prison term for Mark Karpeles, the former CEO of Tokyo-based Mt. Gox, which at one time was the world’s largest bitcoin exchange.

The prosecutors accuse Karpeles of embezzling about 340 million yen from accounts that Mt. Gox managed on behalf of clients, doing so in the final four months of 2013. The prosecutors also say Karpeles used the money for business acquisitions and paying rent.

Karpeles has denied embezzling the funds, saying the money was meant to be accounted as a temporary loan.

In their final argument at the Tokyo District Court, prosecutors said, “There was no documentation of loans and there was no intention of paying back” the money. They demanded a harsh sentence, saying Karpeles betrayed his clients and used a huge amount of their money.

“His responsibility,” the prosecutors said, “is severe.”