Japan's Financial Services Agency (FSA) on Friday morning raided the office of virtual currency exchange Coincheck, which lost 58 billion yen ($530 million) worth of digital currency NEM held by its customers when it was hacked last week, Nikkei Asia Review reported.
The regulator is checking if Coincheck has sufficient funds to compensate customers.
"The investigation is being conducted to protect the current users," Finance Minister Taro Aso said Friday following a Cabinet meeting.
He also demanded customers receive "appropriate" treatment and ordered all other exchanges to report back on their risk management procedures.
The FSA is now probing Coincheck's finances and trying to determine how the hack took place, as well as whether proper security measures have been set up.
Some 260,000 Coincheck customers were victimized in the theft that saw . The company has said it will reimburse them with yen, but questions have emerged about its ability to pay, as well as why it had currencies stored in a hot wallet connected to the internet and thus potentially vulnerable to thieves.