Nvidia’s independent directors retained Wachtell, Lipton, Rosen & Katz and partner Joon H. Kim, the former acting US Attorney for the Southern District of New York who investigated former New York Governor Andrew Cuomo, to lead the board’s inquiry into CEO Jensen Huang’s affair with suspected Chinese intelligence operative Alice Huang. The scandal has erased $428 billion from Nvidia’s market value over two days, and the company and its CEO were hit with a proposed shareholder class action in San Jose federal court alleging they misled investors by downplaying the relationship.

The board probe comes alongside Tuesday reports in The New York Times that Secretary of State Marco Rubio briefed President Donald Trump aboard Air Force One in May about intelligence that Alice Huang was recruited by China’s Ministry of State Security before Jensen Huang joined the presidential trip to Beijing, at least the second warning Trump received in seven months and a contradiction of his Monday denial. Trump said Monday that the FBI is “looking into” the matter and that Jensen Huang told him in a phone call “I had no idea that she was a spy.” Senate Democratic Leader Chuck Schumer called for a full accounting of Trump’s handling of the intelligence, while House Foreign Affairs Committee Chair Brian Mast told ABC News he is prepared to subpoena the Nvidia CEO if he does not respond by Wednesday to a request from three Republican committee chairs for a Nov 18 closed-door briefing.