Xu's temporary detention and subsequent release closely coincides with the period that OKEx's unnamed key holder also became unavailable.
"The private key holder has now returned to his normal business functions," the exchange said in a notice Thursday.
The token has rallied nearly 13% Wednesday.
The pool's hash power has dropped from 5,000 to barely 20 PH/s.
The Chinese government cracks down on the crypto exchanges (again), but Binance has been benefiting.
Huobi said Monday the rumors alleging one of its senior executives had been arrested were false.
While cryptocurrency withdrawals on OKEx remains suspended, the exchange is detailing its plans for the scheduled Bitcoin Cash fork in November.
The OKEx drama shows just how immature crypto markets are compared to traditional ones, but it also highlights their overall resilience.
OKB is trading just above $4, down from nearly $6 before the news.
On Friday morning as the OKEx withdrawal-freeze story twisted and turned, CoinDesk's editors had an off-the-cuff discussion about the fundamental realities and unique challenges of security for even the largest exchanges.
Huobi, one of OKEx’s biggest competitors, ensured its users that its platform is “currently operating normally,” after OKEx announced that it has suspended all cryptocurrency withdrawals indefinitely.
OKEx has denied the ongoing investigation of its founder is related to an anti-money laundering investigation.
OKEx withdrawal suspension sends bitcoin lower, China becomes hotbed of DeFi development, Filecoin first-day trading leaves market cap above $800M.
While market sentiment may remain temporarily weak after the OKEx news, a price crash looks unlikely.
Caixin sources said Mingxing "Star" Xu had been taken by police at least a week ago and hasn't been seen since.