Jensen Huang leads Nvidia, a large US computer chip company. He said on Sunday that he had an affair and was sorry for hurting his wife and children. US officials think the woman, Alice Huang, may have worked as a spy for China. She is not related to Jensen Huang. China says this claim is false.

Nvidia has started its own inquiry. President Donald Trump said on Monday that the FBI is also looking into the case. Jensen Huang told Trump that he did not know Alice Huang might be a spy. It is not clear if she gave any secret information to China. Her location is also unknown.

The case matters because Nvidia makes important chips for artificial intelligence, or AI. The US wants to stop China from getting its best chips because they can help military and security systems. Nvidia is worth about $4.5 trillion. Its leaders say they still support Jensen Huang, but the inquiries will look for any risk to US security.