NEW YORK: Nvidia shed about US$430 billion in market value over two sessions as new reports deepened questions about CEO Jensen Huang's relationship with a Chinese businesswoman alleged to be a spy for Beijing.

The controversy escalated on several fronts on Tuesday as allegations emerged that Huang's relationship with Alice Huang aided at least US$7.5 billion in Nvidia chip shipments to China and that US Secretary of State Marco Rubio had previously briefed President Donald Trump on the affair.

Senate Democratic Leader Chuck Schumer demanded answers from the administration and tighter curbs on chip exports to China, while the company's independent directors hired outside counsel to investigate.