OKEX, one of the world's largest cryptocurrency exchanges, said on Friday it had suspended withdrawals of digital assets, also known as cryptocurrencies.
The exchange said in a statement posted on its website that it was out of touch with one of its private key holders, and that person was cooperating with public security bureau investigations.
The statement did not say which country's security bureau.
A private key provides access to cryptocurrencies.
(Reporting by Alun John and Tom Westbrook; Editing by Tom Hogue)
