A federal judge said yesterday that he will rule within days on a court action seeking the release of a Falls Church man whose family says he is being improperly detained in Saudi Arabia at the behest of U.S. authorities.

The Saudis have not filed criminal charges against Ahmed Abu Ali, a 23-year-old U.S. citizen who has been in custody since June 2003. But the U.S. government said in court papers that the kingdom indicated that it plans to charge him with providing support for terrorism.

Abu Ali, who was studying in Saudi Arabia, was among at least four people arrested last year in a crackdown on a Pakistani organization trying to drive Indian forces out of the disputed Kashmir region. But unlike the other three, who were extradited to the United States and charged, Abu Ali has remained in Saudi Arabia.

Members of Abu Ali's family turned last month to the U.S. courts for help in winning his release. They contend that the United States, not Saudi Arabia, is behind his detention and that he has been denied due process. The prospect of criminal charges has added new urgency to their effort and led them to seek an emergency order from the U.S. District Court for the District of Columbia.

At a hearing yesterday before Judge John D. Bates, Abu Ali's attorney, Morton Sklar, said the charges are a coordinated effort to ensure that Abu Ali remains out of the reach of U.S. courts -- a contention that the Justice Department rejected yesterday.

Even if no charges are filed by Saudi Arabia, the authority of a U.S. court over a prisoner in another country is a matter of much legal debate, lawyers said yesterday.

The Supreme Court ruled this year that the detainees held in Guantanamo Bay, Cuba, have a right to contest their incarcerations in U.S. courts. But no one disputes that the Guantanamo detainees are in the custody of U.S. forces.

By contrast, Abu Ali is being held by the Saudis. But Sklar, executive director of the World Organization for Human Rights, said Abu Ali is effectively in the custody of the United States.

While he acknowledged that the court could not order Saudi Arabia to do anything, Sklar said the judge could order the United States to ask Saudi Arabia not to charge Abu Ali and to return him.

Ori Lev, a lawyer for the U.S. government, attacked Sklar's arguments. Abu Ali is most certainly in the custody of Saudi Arabia, and therefore a U.S. court has no authority in the matter, he said. "The United States does not control Saudi Arabia," Lev said.