The service expressed that a security break including the NiceHash site occurred, which brought about its payment framework being traded off and its Bitcoin wallet being emptied. "Clearly, this is a matter of deep concern and we are working hard to rectify the matter in the coming days", NiceHash said on Facebook.
The company did not respond to requests for comment.
At 1:05 p.m. EST, Bitcoin was valued at $16,825, according to Coinbase, after briefly surging above $19,000 Thursday morning.
While the company hasn't revealed the exact amount that was in the wallet, customers have been circulating a recently created wallet address containing 4736 bitcoins.
The trouble started on 6 December when users of NiceHash, a service which enables people to exchange computing resources known as hashing power to mine for Bitcoin and other cryptocurrencies, began reporting that they had been kicked offline while mining.
NiceHash customers frequently move the cryptocurrency they earn on NiceHash off the service and into their own digital wallets or onto a bitcoin exchange.
Rumours of the hack first appeared early Wednesday, and the site went down for maintenance soon afterward.
When NiceHash admitted that they were hacked, they did not confirm the amount that had been stolen.
Slovenian police are investigating the case together with authorities in other states, spokesman Bostjan Lindav said, without providing details.
NEW YORK (AP) - The price of bitcoin swung wildly Thursday, rising to more than $19,000 only to fall sharply within minutes, as the frenzy surrounding the virtual currency escalated just days before it starts trading on a major USA exchange. A bitcoin is essentially a type of virtual currency that uses the technology of a blockchain in order to make payments securely and store money online.