Tim Montgomery (search) and three other U.S. track athletes were notified by the U.S. Anti-Doping Agency (search) that they may have committed drug violations that could keep them from the Athens Olympics (search).

The letters are the first formal step in USADA's attempt to punish athletes based on documentary evidence instead of a positive drug test.

Montgomery's lawyer, Cristina Arguedas, said the world 100-meter record holder has done nothing wrong and that they will fight any attempt to keep him from running.

"Tim has been a willing participant in the drug testing process and he has passed every test he has ever taken," Arguedas said in a statement Tuesday. "The evidence that we have been shown by USADA and that we are still reviewing is inconclusive and internally inconsistent."

USADA didn't release the names of the athletes, nor specifics of the allegations.

A source within the U.S. Olympic movement, speaking to The Associated Press on condition of anonymity, identified the other three athletes as: Alvin Harrison, an Olympic silver medalist in the 400 meters, and sprinters Christye Gaines and Michelle Collins. Gaines is a two-time Olympic medalist in the 400-meter relay and Collins was the 2003 world indoor champion in the 200.

No letter was sent to sprint star Marion Jones, who is Montgomery's girlfriend and the mother of their child.

USADA said it reviewed thousands of documents seized by federal investigators looking into Bay Area Laboratory Co-Operative, which is at the center of a steroid scandal.

The documents were given to USADA by a Senate committee last month in hopes of guaranteeing a drug-free U.S. Olympic team. USADA, based in Colorado Springs, Colo., has said it can ban athletes without a positive drug test if there is other sufficient evidence.

"The sending of notice letters is the first step towards determining whether sport anti-doping rules have been violated," said Travis Tygart, USADA's director of legal affairs.

The next step, USADA said, is for an independent review board to examine the cases and recommend whether the anti-doping agency should proceed with a formal charge.

Montgomery and Jones have denied using any performance-enhancing drugs, and Jones has promised court action if an attempt is made to punish her without a positive test.

"It is fundamentally unfair to try to take away an athlete's reputation, their work, and their dreams based on meager information, flimsy documents and a flawed process," Arguedas said.

Montgomery recently left coach Dan Pfaff to return to his former coach, Steve Riddick. Pfaff remains Jones' coach.

USADA handles drug matters under contract with the U.S. Olympic Committee and USA Track & Field, the sport's governing body in the United States.

"We are committed to taking a team to the Athens Games that represents the highest standards of fair play and clean competition — a team that will make America proud — and we appreciate and commend USADA for its efforts in helping us reach this important goal," USOC spokesman Darryl Seibel said in a statement.

Arguedas met with USADA officials last week in San Francisco to review the evidence from the federal grand jury investigation into BALCO. Montgomery and Jones were among dozens of athletes who testified to the grand jury.

BALCO founder Victor Conte and three other men, including the personal trainer of baseball slugger Barry Bonds, are charged with illegally distributing steroids to professional athletes. All four pleaded innocent. No athletes have been charged.

The San Jose Mercury News reported two weeks ago that Montgomery was involved with Conte in a plan devised in 2001 to help him set the world record. The plan, according to the newspaper, called for Montgomery to take THG, a steroid that was undetectable until last summer.

Another of those connected with the probe, world champion sprinter Kelli White, has accepted a two-year ban after being confronted with documents alleging her use of steroids.