Japan's financial regulator plans to slap an administrative punishment on cyrptocurrency exchange operator Coincheck Inc on Monday, the top government spokesman said, after the firm lost 58 billion yen ($534 million) worth of NEM coins to hackers.

Tokyo-based Coincheck on Friday suspended trading in all cryptocurrencies except bitcoin after the theft of NEM coins in one of the biggest-ever losses of digital money to hackers. It said on Sunday it would return about 90 percent with internal funds, though it has yet to figure out how or when.

The Financial Services Agency (FSA) will issue a business improvement order to Coincheck later Monday, Chief Cabinet Secretary Yoshihide Suga told a regular news conference.

- Reuters