SAN FRANCISCO -- A year after a container ship spilled nearly 54,000 gallons of oil into the San Francisco Bay, a federal magistrate ruled in San Francisco Friday that two crew members can return to China later this month.

The two men are among six Chinese crew members of the Cosco Busan, which spilled the bunker fuel into the Bay after hitting a protective fender of a San Francisco-Oakland Bay Bridge support tower Nov. 7, 2007.

The crew members have not been charged with any crimes, but have been required to stay in San Francisco as material witnesses in the pending criminal case of the ship's pilot, John Cota, and management company, Hong Kong-based Fleet Management Ltd.

Lawyers for Cosco Busan bosun Liang Xian Zhang and helmsman Zong Bin Li asked U.S. Magistrate Joseph Spero to release the men because they have completed or nearly completed videotaped pretrial depositions, or sworn statements.

Spero agreed Friday that they could leave the country, but imposed a condition that they must accept subpoenas to testify, if asked, in the trial of Cota and Fleet Management in federal court in San Francisco in April. They must also review and sign their depositions.

Jonathan Howden, a lawyer for Zhang and Li, argued unsuccessfully that they should be released without conditions because they have been forced to stay in a foreign country for a year.

Howden quoted Li as saying, "I want to return home so that I can be free."

Spero said that Zhang, who has completed his deposition, can leave Nov. 17, and Li, whose deposition is scheduled to be completed next week, can leave Nov. 21.

Outside of court, Howden said he doesn't expect to appeal the ruling. The attorney said, "I don't have time to appeal. I want my clients to be able to go home."

The depositions of the remaining crew members are slated to be completed by mid-December.

Cota, 60, of Petaluma, and Fleet Management are charged with negligently polluting the bay, killing migratory birds and making false statements.