Cryptocurrency firm Tech Bureau Corp. has failed to provide adequate details on how thieves hacked into its exchange to steal ¥7 billion ($62 million), or explained its delay in reporting the hack, the country's financial regulator said on Tuesday.

The Financial Services Agency issued a business improvement order to the Osaka-based firm ordering it to provide details how the theft occurred and how it would compensate clients. It was the third business improvement order served on the firm.

Tech Bureau said last week its Zaif exchange was hacked and ¥7 billion worth of bitcoin and other cryptocurrencies were stolen.