Some 58 billion yen ($533 million) in cryptocurrency has disappeared from a Japanese exchange due to hacking, local media reported Saturday.

The Coincheck exchange, the operator of the cryptocurrency called NEM, said on its website on Friday that it had suspended sales and withdrawals of the currency as well as trades of most other cryptocurrencies and the Japanese yen.

Speaking at a news conference late Friday, Coincheck president Koichiro Wada apologized for the incident and said the company might seek financial assistance, the Kyodo News agency reported.

Coincheck, which calls itself the leading Bitcoin and Cryptocurrency exchange in Asia, said it had detected the unauthorized access to the system shortly before 3 am Friday (1800 GMT Thursday).

The exchange has already reported the incident to the police and to Japan's Financial Services Agency, NHK said.

In 2014, Tokyo-based Mt. Gox, which once handled 80 percent of the world's bitcoin trades, filed for bankruptcy after losing some 850,000 bitcoins - then worth around half a billion U.S. dollars - and $28 million in cash from its bank accounts.