"The airport police told him he couldn't park his car there and he said, 'Write me up a ticket and I'll pay for it,'" Towers said. "He was arrested."

Barry Bonds, already under investigation for lying under oath about his steroid use, failed a test under Major League Baseball's amphetamine policy last season and then initially blamed it on a teammate, the Daily News has learned.

Under the policy, which went into effect only last season, players are not publicly identified for a first positive test.

But according to several sources, when first informed by the MLB Players Association of the positive test, Bonds attributed it to a substance he had taken from the locker of teammate Mark Sweeney. Sources did not identify the drug in question but characterized it as a serious stimulant.

When asked last night whether Bonds had an explanation for why he failed the test or if he wanted to issue a denial, Bonds' agent, Jeff Borris, said, "I have no comment on that."

Giants officials did not return calls seeking comment last night.

Bonds, who has long defended himself against steroid accusations by saying he "never failed a drug test," did not appeal his positive test, but was immediately subject to an additional six drug tests by MLB over the next six months.

Sweeney declined comment, but his agent, Barry Axelrod, told the News, "Mark was made aware of the fact that his name had been brought up, but he did not give Barry Bonds anything and there was nothing he could have given Barry Bonds."

Bonds was not punished for his transgression, but instead was referred to treatment and counseling. While amphetamines are considered performance-enhancing drugs, they are treated differently than steroids under baseball's drug policy. Had Bonds failed a steroid test, he would have been suspended for 50 games, but under baseball's amphetamine policy no one is publicly identified or suspended until a second positive, which would result in a 25-game suspension. A player is suspended for 80 games for a third positive.

The policy covers a range of stimulants, including the ubiquitous "greenies," or Dexedrine. Benzedrine, ephedrine and the stimulants Ritalin and Adderall, which are used to treat attention-deficit disorder, are among the substances on the policy.

"We're not in a position to confirm or deny, obviously," MLB spokesman Rich Levin said. "A second failed test would mean a suspension."

Sources said Sweeney, a first baseman/outfielder, first heard about the test when Gene Orza, the chief operating officer of the players association, called to say the player's name had been dragged into the controversy.

Orza told Sweeney that if he had anything troublesome in his locker, he should remove it and that he should not be sharing substances with other players. Sweeney told Orza that there was nothing in his locker that would be of concern, sources said.

Axelrod would not comment on the conversation between Orza and Sweeney. Orza also refused to comment on what he said to Sweeney or about Bonds' failed test, but added, "I can say unequivocally in my 22 years I've known Barry Bonds he has never blamed anyone for anything."

Sweeney apparently confronted Bonds, and Bonds told him that Orza had misunderstood, that he had not intended to implicate his teammate.

Bonds has been in the doping spotlight since September 2003, when federal agents raided the BALCO lab and the home of Bonds' personal trainer, Greg Anderson. Bonds testified before a grand jury in the steroid-trafficking case that he had taken substances identified by the government as steroids, but that he believed they were legal supplements. A Daily News reporter overheard part of his testimony that day admitting he had unknowingly used steroids, and a year later the San Francisco Chronicle published extended excerpts from the grand jury transcripts.

The leaks about Bonds' steroid use were not sufficient evidence to allow MLB to test Bonds for cause, but the failed amphetamine test is.

BALCO founder Victor Conte, Anderson and three other men served prison sentences for their parts in the trafficking ring, and Bonds has been under investigation for perjury and tax evasion for more than two years. Anderson is in prison on a contempt charge for refusing to testify against his longtime friend.

Long before steroids took hold in clubhouses in the early 1990s, amphetamines were the performance-enhancer of choice in baseball.

Even when baseball first adopted a steroids policy in 2003, amphetamines were not specifically banned or tested for, although many are illegal without a prescription.