LONDON (Reuters) - Bitcoin slid as much as 14 percent on Tuesday to hit a four-week low below $12,000, as fears grew of a regulatory crackdown after reports that South Korea’s finance minister had said banning trading in cryptocurrencies was still an option. South Korean news website Yonhap reported that Finance Minister Kim Dong-yeon had told a local radio station that the government would be coming up with a set of measures to clamp down on the “irrational” cryptocurrency investment craze.