Singapore’s government said on Thursday the United States had provided little help in its investigation into Alice Huang, the woman at the center of a spy plot that has led to the investigation of Nvidia’s chief executive, Jensen Huang.

Singaporean authorities held Ms. Huang’s passport to prevent her from leaving the country from June 2025 until February over “potential false declarations” in relation to her company, Megaspeed, which is based in the country, the government said in a statement. She was ultimately released with a “stern warning” and barred from re-entering Singapore.

The statement raises new questions about the response of the Trump administration to the case and why the U.S. government did not more forcefully intervene. According to the timeline in the statement, Singaporean authorities had been holding Ms. Huang’s passport well after President Trump was briefed last fall about her relationship with Nvidia’s chief executive and the belief that she was a Chinese intelligence asset.

The New York Times has reported that Taiwan began monitoring Ms. Huang in 2024 at the guidance of the U.S. government.