Ethereum dives as one of the world's biggest cryptocurrency markets considers a bill to ban trading

South Korea's justice minister said that the country is preparing a bill that will ban all cryptocurrency trading

Park Sang-ki told reporters that there are "great concerns" regarding virtual currencies

Bitcoin tumbled more than 12 percent following Park's remarks before recovering.

Ethereum tanked on the news and is still down 7.6 percent on the Coinbase exchange.

South Korea's justice minister said on Thursday that a bill is being prepared to ban all cryptocurrency trading in the country.

That news is a major development for the cryptocurrency space, as South Korea is one of the biggest markets for major coins like bitcoin and ethereum.

According to industry website CryptoCompare, more than 10 percent of ethereum is traded against the South Korean won — the second largest concentration in terms of fiat currencies behind the dollar. Meanwhile, 5 percent of all bitcoin are traded against the won.

"There are great concerns regarding virtual currencies and justice ministry is basically preparing a bill to ban cryptocurrency trading through exchanges," Park Sang-ki said at a press conference, according to the ministry's press office.

Bitcoin tumbled more than 12 percent following Park's remarks, before recovering. It was down 0.7 percent on the Coinbase exchange.

Ethereum tanked on the news and remained 7.6 percent lower on Coinbase.

Park added that he couldn't disclose more specific details about a proposed shutdown of cryptocurrency trading exchanges in the country, adding that various government agencies would work together to implement several measures.

Later in the day, South Korea's presidential office said that any potential bill "is not a measure that has been finalized," according to News1, a South Korean news site.