Police are questioning a Japanese man who accepted a cryptocurrency called NEM in exchange for another virtual currency.
Sources close to the investigation say that Tokyo Metropolitan Police investigators learned the man acquired NEM knowing that it was money taken from Tokyo-based cryptocurrency exchange Coincheck.
He said that he purchased it at a lower rate.
Coincheck had suffered unauthorized access to its system last month and NEM coins worth about 530 million dollars were allegedly stolen.
The money was moved to multiple online accounts. And some of the transferred funds have been converted to other virtual currencies on black market websites known as the "dark web".
Police in Tokyo tracked online activity and discovered that the Japanese man got a small amount of money.
He is believed not to be involved with hacking and the police are closely monitoring any moves to convert the missing NEM.