Bitcoin's price fell by around 10% on Sunday in the wake of a hack on South Korean cryptocurrency exchange Coinrail which reportedly saw around $40 million in virtual coins stolen.
On its website, Coinrail says a "cyber intrusion" led to the theft of around 30% of the coins traded on its exchange.
While the hack affected lesser known ERC-20-based tokens on a small exchange, the news still saw Bitcoin and other more established cryptocurrencies tumble.
Bitcoin hit a two month low of $6,647.33 on Sunday before recovering slightly but is still trading well below $7000. Ethereum and others also saw their prices drop.
Coinrail has suspended trading and is cooperating with a police investigation.