TOKYO (Reuters) - A Japanese cryptocurrency exchange undergoing checks by regulators has said a system failure let investors briefly trade a digital currency for zero yen, highlighting security concerns about such assets after last month's cyber heist at Coincheck Inc.
Zaif, an exchange run by Osaka-based Tech Bureau Corp, said on Tuesday a problem in its price calculation system allowed seven customers to trade a cryptocurrency with no yen value for around 20 minutes on Feb. 16.
The company did not identify the cryptocurrency. A representative of Tech Bureau was not immediately available for further comment.
The incident comes after hackers stole $530 million in digital money from Coincheck last month, sparking checks by regulators of Japan's other exchange operators, including Tech Bureau.
The Financial Services Agency launched on-site checks at Tech Bureau because it saw the exchange as potentially vulnerable to cyber-attacks, a person with direct knowledge of the matter told Reuters on Feb. 9.
Japan last year rolled out the world's first system to oversee cryptocurrency exchanges, in a bid to protect customers, stamp out illegal uses of cryptocurrencies as it sought to nurture a young and promising sector.
Zaif is one of 16 cryptocurrency exchanges registered with the government. Regulators have allowed a further 16, including Coincheck, to continue operating pending full registration.