Nvidia has hired New York law firm Wachtell, Lipton, Rosen & Katz to investigate the affair between its chief executive and an alleged Chinese spy.

Jensen Huang, a co-founder of Nvidia who has led it to become one of the most valuable companies in the world, admitted to having a romantic relationship with a woman outside of his marriage.

The woman, Alice Huang, is alleged to be a spy for Beijing. She was an executive at a Singaporean company Megaspeed, which has been a customer of Nvidia.

Nvidia said on Tuesday that Wachtell attorney Joon Kim was set to lead “a thorough and independent investigation” into Jensen Huang’s affair. The FBI is also conducting its own probe.

Nvidia is widely considered one of the most important companies behind the US artificial intelligence (AI) boom given it is the sole manufacturer of a crucial computer chip required for successfully operating AI tools.

Shares in the company fell to a near-yearly low on Tuesday, wiping more than $500bn (£375bn) off Nvidia’s stock market value since Friday, even as tech stocks have recovered since last week’s sell-off.

Jensen Huang’s relationship with an executive of an Nvidia customer, who is also believed by the US government to be spying for China, has business and national security implications.

Megaspped had been suspected of helping divert Nvidia chips to China, a concern that Nvidia has maintained was investigated and debunked.

According to the New York Times, Secretary of State Marco Rubio sent a memo to top officials in Washington in spring of this year warning that the Nvidia boss was in a close relationship with a Chinese spy.

Beijing has rejected claims that Jensen Huang has been targeted, with its foreign ministry saying the allegations were “intended to smear and malign China”.

US President Donald Trump said Monday that he had spoken to Jensen Huang and that the Nvidia boss told him “I had no idea she was a spy.” Trump said he believed the him.

When announcing on Sunday that it would investigate the affair, Nvidia’s board said it had no reason to believe the company’s secrets or national security were compromised.

However, the relationship has drawn political attention. Congressional leaders of the House Committee on Foreign Affairs have asked Jensen Huang to appear next week for a closed door briefing.

The Nvidia boss has yet to say whether he will attend, a person familiar with the committee’s demand told the BBC.

Committee chair congressman Brian Mast said he would subpoena Jensen Huang, effectively forcing him to appear before the committee, if necessary.