US President Donald Trump has said that the FBI is looking into Nvidia CEO ‌Jensen Huang’s affair with a Chinese businesswoman alleged to be a spy for Beijing.

Mr Trump said that he “was amazed” by allegations about Mr Huang, among the president’s closest allies in Silicon Valley.

Mr Trump added that he had spoken to the CEO, who told him that he had no idea that the woman is a spy.

Nvidia shares closed down more than 4 per cent on Monday after the company’s board launched an internal investigation into whether Mr Huang had been targeted by a foreign intelligence effort.

The probe has put a spotlight on the 63-year-old Nvidia chief’s future given the company’s status as the world’s most valuable chipmaker and its CEO’s role as the most prolific salesman of ⁠the AI boom.

Mr Huang told Nvidia’s employees that he had been unfaithful to his wife, without disclosing details of the relationship.

The leather-jacketed Huang enjoys rock-star status worldwide, particularly in Asia, where he often mingles freely with fans, taking selfies and signing autographs for his devoted followers.

He is Nvidia’s fifth-largest shareholder with a roughly 3.6 per cent stake, according to LSEG data, and keeps a tight ​grip on the company through an unusually flat structure in which dozens of executives report directly to him.

But unlike Mark Zuckerberg’s Meta Platforms or Elon Musk’s SpaceX, Nvidia has no dual-class shares that would give co-founder Huang majority voting control.

The New York Times reported that Mr Trump was briefed on Mr Huang’s relationship with the woman.

It added that she was giving information to the Chinese government and that the president chose not to act on​the information.

“The so-called Chinese spy narrative is purely a groundless accusation, slander and a smear,” Chinese Foreign Ministry spokesperson Guo Jiakun told reporters in Beijing.