South Korea has banned anonymous bank accounts being used to buy and sell cryptocurrencies, a widely-anticipated move in one of the world's most popular Bitcoin markets.
The measures are designed to prevent children and criminals from trading Bitcoin in a country that has embraced the digital currency amid its rapidly-ascending price.
Bitcoin fell from just under $11,000 (£7,800) to as low as $10,179 on Tuesday morning after the move, as investors feared the crackdown could damage demand. It is trading close to its lowest levels in three months, having halved in value since mid December.
Actions in South Korea have an outsized influence on Bitcoin's price. It is the world's third-biggest market for the digital currency after Japan and the US, and demand has meant the cryptocurrency trading hands at higher prices in the country than elsewhere.
However, the relative lack of regulation has concerned authorities, who fear that money launderers outside of South Korea may be exploiting the relatively light-touch laws.