SAN FRANCISCO — A federal appelate judge has ordered the preservation of all evidence that allegedly shows 104 Major League Baseball players tested positive for steroids in 2003.

The 9th U.S. Circuit Court of Appeals last month ruled that federal agents wrongly seized the material from drug testing labs when they were authorized to take only evidence related to 10 players listed in their search warrant.

If the ruling stands, the baseball players’ association will be free to order the destruction of all the test results and related material, except for the 10 players listed in the warrant — and that’s what federal prosecutors fear.

Prosecutors on Tuesday urged Chief Judge Alex Kozinski to freeze the legal proceedings until they decide whether to ask the U.S. Supreme Court to review the case. They said it appeared the 9th Circuit’s decision conflicts with prior high court rulings dealing with proper search and seizures of property.

Federal agents raided the offices of baseball’s drug-testing companies in April 2004, seized a spreadsheet containing the drug-testing records of all baseball players, mixed in on a computer with those from other sports and businesses, then obtained additional search warrants.

Prosecutors argued they had a ‘‘plain-view’’ right to the records of all baseball players who they said tested positive.