The government's already broad investigation into athlete steroid use appears to have widened even more, with the names of 100 baseball players who tested positive for illegal drugs now in the hands of federal investigators.

The information, which an appeals court granted to authorities Wednesday, could help the government pinpoint the source of steroids in baseball and also bolster the perjury case against Barry Bonds, who is under investigation for telling a grand jury he never knowingly used performance-enhancing drugs.

The ruling by the 9th U.S. Circuit Court of Appeals gave investigators access to data from confidential drug tests by Major League Baseball in 2003.

It's unclear if Bonds' results are among those confiscated during the 2004 raids on two labs that conducted the tests.

Even so, the players who are found to have tested positive for steroids could be called to testify about how they obtained the drugs. If enough testify that they got them from Bonds' personal trainer, Greg Anderson, it could undermine the slugger's claim that he didn't know Anderson was supplying him with illegal substances.

Anderson is currently in prison for refusing to testify in the perjury probe. He was previously convicted of steroids distribution.

Bonds' lawyer questioned why the government continues to pursue Bonds when he doesn't believe the Giants' outfielder was among those who tested positive in 2003.

"If Barry is one of the players that did not test positive in '03 for steroids, I would hope that it would cause the government to rethink their continuing harassment they've engaged in for years," attorney Michael Rains said Wednesday.

The samples were collected in 2003 at baseball's direction as part of a survey to gauge the prevalence of steroid use. Players and owners agreed in their labor contract that the results would be confidential, and each player was assigned a code number to be matched with his name.

Quest Diagnostics of Teterboro, N.J., one of the largest drug-testing firms in the nation, analyzed more than 1,400 urine samples from players that season. Comprehensive Drug Testing of Long Beach, Calif., coordinated the collection of specimens and compiled the data.

The testing was part of baseball's effort to determine whether a stricter drug-testing policy was needed. Because 5 percent or more of the tests for steroids came back positive, it automatically triggered the start of testing with penalties in 2004.

Bonds has always maintained he never tested positive for illegal drug use. However, federal investigators demanded to see the 2003 test results for Bonds, then-New York Yankees Gary Sheffield and Jason Giambi, and seven other players.

When they raided the testing labs for those 10 results, investigators also seized computer files containing the test results of nearly 100 other players not named in the government's subpoena and warrants.

The players' union sued to keep the government from accessing the records, saying the seizures violated the players' constitutional rights.

The appellate panel ruled 2-1 Wednesday against that claim, overturning decisions by three lower courts in San Francisco, Los Angeles and Las Vegas.

The key opinion, which says federal prosecutors are entitled to the urine samples and names of those who tested positive, overturns a ruling by U.S. District Judge Susan Illston. The San Francisco-based judge had quashed the subpoenas to seize the test results, saying they constituted harassment and were unreasonable.

"The district court rested its order on legally insufficient grounds, and abused its discretion in granting the motion to quash," Judge Diarmuid F. O'Scannlain wrote for the appeals court in the 120-page decision.

In dissent, Judge Sidney R. Thomas voted to uphold Illston, writing that the government's action "suggests an abuse of grand jury process."

U.S. Attorney Kevin V. Ryan of San Francisco said the office is reviewing the decision "to determine what the next investigative step may be."

The players' union can ask for a new hearing before the full 9th Circuit or appeal the panel's ruling to the U.S. Supreme Court.

The union's general counsel, Michael Weiner, declined to immediately comment, saying he wanted to first review the decision.

Separately, the court also ruled that "the government's seizures were reasonable under the Fourth Amendment" and sent the case back to the district court to review what evidence can be used and what must be returned.

The government's investigation of the Bay Area Laboratory Co-Operative, a now-defunct Burlingame supplements lab at the center of the steroid scandal, already has resulted in guilty pleas from BALCO president Victor Conte, Anderson, BALCO vice president James Valente, chemist Patrick Arnold and track coach Remi Korchemny.

The case is United States v. Comprehensive Drug Testing Inc., 05-10067.