The Justice Department in May sued for a court order forcing Wynn, the former CEO of Wynn Casinos, to register under the Foreign Agents Registration Act (FARA). Officials alleged that Wynn lobbied then-U.S. President Donald Trump on China's behalf in 2017. Wynn's attorneys denied that he was ever an agent of the Chinese government.

U.S. District Judge James Boasberg said Wednesday that, because any relationship between Wynn and the Chinese government ended in 2017, the GOP donor cannot be required to register as an agent. The judge pointed to past precedent in D.C. federal court in making the ruling.

The judge said he was not determining whether Wynn had lobbied on China's behalf. He also said the Justice Department could pursue criminal sanctions against Wynn for failing to disclose the alleged lobbying, if the statute of limitations had not expired.

Wynn's lawyers and the Justice Department did not immediately respond to requests for comment.

(Reporting by Jacqueline Thomsen in Washington; Editing by David Bario and Louise Heavens)

By Jacqueline Thomsen