Japan’s Financial Services Agency (FSA) on Monday ordered improvements to operations at Tokyo-based Coincheck, after hackers stole 58 billion yen ($534 million) of NEM coins, AFP reported.
The watchdog said in a statement that it had ordered Coincheck to investigate the cause of the incident, "properly" deal with clients, strengthen risk management and take preventive measures. It also warned the office would be raided if necessary.
The agency will supervise Coincheck to ensure the measures are being implemented and contracts are being honoured, Chief Cabinet Secretary Yoshihide Suga said at a regular briefing.
"While examining the cause of the incident and taking necessary measures, we want the ministries and agencies concerned to urgently study what further measures we'd need," he said.
Coincheck suspended trading of all cryptocurrencies except Bitcoin on Friday, and said it had lost 523 million units of NEM.
The exchange has said it will use its own funds to reimburse about 46.3 billion yen (around $430 million) - at a rate of 88.549 yen per NEM - to all 260,000 customers who lost their holdings. The company said it would reimburse customers in yen, not cryptocurrency.
The Financial Services Agency is also carrying out checks at other exchanges in the wake of the theft to detect potential security problems.