Bitcoin exchange Mt. Gox Co. apparently ran out of money six months before it announced in February 2014 that it was filing for bankruptcy after tens of millions of dollars worth of the virtual currency and client funds disappeared, investigative sources said Tuesday.

The Tokyo-based company seems to have been running a deficit on its balance sheet and started paying some clients with money drawn from other customers' accounts, the sources said.

The fresh allegations emerged after the arrest Saturday of Mark Karpeles, its 30-year-old founder and CEO, for allegedly manipulating virtual currency data to pad his personal cash account. Karpeles, a French national, has denied the charge, according to Tokyo police.