The CEO of the troubled exchange had presented "a lot of urgency" in seeking that amount of cash injection during a call on November 8, as this would have helped FTX survive a short-term liquidity crisis, said Lennix Lai, director of financial markets at OKX.

The appeal for cash injection has come as FTX was facing a $7 billion total liability, said Lai, citing Bankman-Fried's comment made in the call.

FTX has approached OKX for a deal as it needed to survive through a slew of withdrawal requests, Lai said, citing the several calls he had with Bankman-Fried on Nov. 8.

"If FTX does not get immediate cash injection, they would go bankrupt," said Lai, he recalled their conversation during a later call at 7 a.m. Hong Kong time.

"Sam said he was talking with a few other potential investors, so he needed an urgent decison from us," he said.

(Reporting by Georgina Lee; Editing by Jacqueline Wong)