SEOUL--South Korea's national spy agency told a parliamentary committee it was possible North Korean hackers broke into a cryptocurrency exchange in Japan to steal $530 million (58 billion yen) worth of digital coins, a person familiar with the matter said on Tuesday.

"It's a possibility that North Korea may be behind the theft," the person, who had knowledge of Intelligence Committee proceedings, told Reuters.

The person, who declined to be named due to sensitivity of the issue, added the virtual coin market remains a likely target for North Korean hackers due to its sheer size and light regulation but that there was no hard evidence that North Koreans were behind the theft.

Japan's cryptocurrency exchange Coincheck Inc was raided on Friday to fix flaws in its computer networks that existed well before hackers stole $530 million of digital money in January.