Legislative oversight of Nvidia and U.S. advanced chip export policy is intensifying. Tim Scott, chairman of the Senate Banking Committee, sent letters Thursday evening to Jensen Huang, who recently stepped down as Nvidia’s chief executive officer, and Commerce Secretary Lutnick, asking them to attend committee hearings on Dec. 3 and Dec. 10 to answer questions on Nvidia-related controversies, corporate governance and the Commerce Department’s role in chip policy.

The letters show that Scott wants Huang to testify about recent public reports surrounding Nvidia, including policy disputes involving the global artificial-intelligence chipmaker. Because Nvidia sits at the center of discussions over U.S. advanced chip export controls, its governance and business moves have drawn congressional scrutiny. Scott said in the letter that if Huang does not appear voluntarily, the committee will consider issuing a subpoena.

A separate letter to Lutnick focuses on the Commerce Department’s role in shaping and enforcing export controls. Republican lawmakers have increasingly questioned the department’s chip policy, and the hearing will ask Lutnick to respond to public reports tied to Nvidia and the department’s role. The letter says the developments involve significant national-security and economic interests, making timely and in-depth congressional involvement necessary. As of the time the reports were published, the Commerce Department, Huang and Nvidia had not immediately responded to requests for comment.