Nvidia's board is preparing to oust CEO Jensen Huang after he had two extramarital affairs, including one with a suspected Chinese spy, the Wall Street Journal is reporting.
The board is preparing to meet as soon as Wednesday to determine his future, the report said.
Huang's potential departure would leave a leadership vacuum at the roughly $US4 trillion ($A5.8 trillion) chipmaker he co-founded and built over more than three decades to become the dominant supplier of AI chips at the centre of the global artificial-intelligence boom and US-China technology rivalry.
The company's shares slid about eight per cent in after-hours trading. Including Wednesday's after-hours selloff, Nvidia has lost about $US600 billion ($A876 billion) in stock market value this week since the board announced its investigation.
"Huang being removed immediately could be challenging for Nvidia since it does not have a succession plan in place ... If Mr. Huang broke the law or violated company policies, the board is likely to act as soon as they have proof," Gil Luria, head of technology research at D.A. Davidson, said.
Earlier in the day, the New York Times reported that Huang had an extramarital affair with a company executive who reported to him.
The relationship was with Kimberly Powell, Nvidia's vice president of healthcare, the New York Times said, citing five people who worked at the company.
When reached by phone Wednesday and asked about his relationship with Powell, Huang said, "I don't think you should be talking to me directly." He then hung up, the New York Times reported.
Nvidia and Powell did not immediately respond to requests for comment. Reuters could not immediately verify the reports.
The reports mark a sharp escalation in a controversy that began with revelations about Huang's relationship with Alice Huang, a woman US intelligence has said was involved in facilitating shipments of Nvidia chips to Chinese firms.
In a memo to employees on Sunday, Huang acknowledged being unfaithful to his wife and took "full responsibility," but gave no details about the relationship.
The same day, Nvidia's board launched an investigation into whether Huang had been targeted by a foreign intelligence operation. The probe is being overseen by independent directors with outside legal counsel. At the time, the board expressed confidence in Huang.
US President Donald Trump has said he had not discussed the allegations with Huang but voiced support for the Nvidia chief, calling him "an honourable guy" who had "done an amazing job for our country".
Huang faces a potential congressional subpoena if he doesn’t respond to a request to provide a closed-door briefing about the allegations that he had a close relationship with the Chinese businesswoman who passed information to Beijing.
Huang co-founded Nvidia in 1993 with Curtis Priem and Chris Malachowsky. Its early hits were graphics chips for computer games, before its CUDA software opened the processors to general computing and, later, AI.
