US President Donald Trump has said the FBI is investigating the affair between the chief executive of Nvidia and an alleged Chinese spy.

Trump said he spoke to Jensen Huang on Monday following reports that the US believed he had been targeted in a Chinese espionage campaign.

“I asked him that question, ‘Did you have any idea she was a spy?’ He said ‘I had no idea she was a spy’ and I really believe him,” Trump told reporters.

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

Nvidia, which has commissioned an independent investigation into the affair involving Alice Huang, alleged to be a Chinese spy, said it had no reason to believe the company’s secrets or national security were compromised.

Nvidia is the world’s second most valuable company after Apple, and designs computer chips that have become central to AI technology. The revelations knocked about $250bn (£190bn) off its value on Monday as the company’s share price fell by more than 4%.

Trump later told reporters at the White House that the FBI was looking into the issue, but did not elaborate on the investigation, or when it was launched. The FBI declined to comment when contacted by the BBC.

US intelligence officials believe Alice Huang, also known as Huang Le, was a spy for Beijing, according to a New York Times report. She is not related to Jensen Huang.