Troubled Bitcoin exchange Mt. Gox says that it located nearly a quarter of the around $485 million worth of missing bitcoins that it's been searching for since shutting down its site and filing for bankruptcy protection late last month. Mt. Gox, once Bitcoin's top exchange, previously chalked much of the currency's disappearance up to hackings over the course of several years, leading to some obvious questions about its accounting practices and how this could have gone unnoticed until recently. In finding the bitcoins again, questions about its accounting practices sound just as loudly: it claims to have found the bitcoins — approximately 200,000 of the missing 850,000 — in an old wallet that it mistakenly thought was empty.

"The reasons for their disappearance ... is still under investigation."

Mt. Gox says that it now holds approximately 202,000 bitcoins, with 650,000 still missing. Given the dramatic change in circumstance overnight, the exchange warns that the figure missing is still subject to change — as are the suspected reasons for their disappearance. "Please note that the reasons for their disappearance and the exact number of bitcoins which disappeared is still under investigation," Mark Karpeles, Mt. Gox's CEO, writes in a statement. The found bitcoins have since been moved offline for safekeeping.

It's unclear what Mt. Gox will do with any bitcoins that it locates, as the vast majority of the currency it lost belongs to its customers. While this discovery may raise hopes that some could see their fortunes return, the exchange is still a ways away from locating the entirety of the bitcoins it was accountable for. Still, this raises the possibility that Mt. Gox does in fact have access to more bitcoins than it believes — or than it has let on, as some irritated observers have posed.