The Court of Appeal said in a decision issued Monday that the case is moot because the children are in Russia with their grandmother and are unlikely to return in the wake of their father's conviction for murdering their mother.

Justice Henry Needham wrote for a three-judge panel, "The controversy before us has become an abstract proposition."

Reiser, 44, of Oakland, a computer file systems developer, was convicted in April of murdering his estranged wife Nina, 31, in September 2006. He is due to be sentenced in Alameda County Superior Court on Friday.

After Nina Reiser disappeared on Sept. 3, 2006, the county juvenile court took jurisdiction over the children, then-7-year-old Rory and 5-year-old Nio.

A judge gave the children's maternal grandmother, physician Irina Sharanova, permission to take them to her home in St. Petersburg for the Christmas holidays in 2006. The grandmother did not return them in January 2007 as ordered.

The juvenile court later in 2007 concluded that the grandmother's home was a good placement and allowed the children to be placed there for the time being.

But a judge also issued two orders requiring the children to be brought to Alameda County for evaluations, first in August 2007 and again in November when Rory returned to Oakland with his grandmother to testify in the trial.

But the boy went back to Russia with his grandmother without reporting to the juvenile court.

Lawyers for the children, backed by the county prosecutors and the U.S. Justice Department, claimed the children were protected from appearing in juvenile court by a treaty between the United States and Russia.

The treaty provides Russian residents a "safe passage" to come to the United States to testify in a criminal trial without being arrested or detained in connection with any other proceeding.

The juvenile court judge contended the treaty didn't prevent his court from ordering the appearance of children in its jurisdiction.

Although the children were back in Russia, their lawyers appealed the orders because they said they feared that if Reiser wins appeals, his case might be reopened and the children might be recalled as witnesses.

But the appeals court said it didn't have to decide at this point whether juvenile court law takes precedence over the international treaty.

Needham wrote, "We do not think it would be prudent to offer an advisory opinion on an international agreement between two nations in a case where it will have no practical effect."

The panel said that if Reiser's case is ever reopened and the children are ever recalled as witnesses, they can file a new legal challenge seeking protection under the treaty.

The justices said, "The minors' presence in Russia makes it impossible for us to fashion an effective remedy ... Moreover, the effective dates of the challenged orders have passed and father's subsequent conviction for murder makes it extremely unlikely the minors will return to this country under the provisions of the treaty."

In two earlier rulings this year, the appeals panel upheld the placement of the children with their grandmother, rejecting challenges by Hans Reiser.