Last week, prominent sprint coach and Olympic gold medalist Jon Drummond unmasked himself as the target of a U.S. Anti-Doping Agency investigation when he filed a defamation lawsuit in Texas against sprinter Tyson Gay—his former protégé—and USADA CEO Travis Tygart.

Gay, the top American sprinter of the current generation, failed a series of drug tests last summer and has since been cooperating with USADA investigators. Earlier this month, USADA announced it would halve the typical two-year ban for Gay because he provided information on others potentially involved in doping. ProPublica reported previously that Gay told USADA that Drummond, chair of USA Track and Field's Athletes Advisory Committee, encouraged his use of supposed anti-aging creams that contained banned substances.

Drummond's suit, for the first time, details a more serious array of allegations involving his work with Gay. In it, Drummond accuses Gay of falsely implicating him in doping, and Tygart of doing the same when he said publicly that Gay had earned a reduced ban for providing "truthful assistance." USADA notified Drummond last month that it would seek a lifetime ban against him, according to the suit filed in Tarrant County Civil Court. Drummond subsequently learned that Gay had told USADA that "Mr. Drummond had personally injected Gay with various substances," the suit said, and that "Mr. Drummond had discussed the possibility of facilitating Mr. Gay's use of HGH," or human growth hormone, which is used by athletes for muscle building and fat cutting.

The court filing marks the first time these claims have been made public. In a statement released by his lawyer, Drummond "categorically denies ever having encouraged Tyson Gay, or any other athlete, to use any banned substance."

Drummond's reference to a lifetime ban suggests that he received a USADA "notice," which is given to individuals accused of doping offenses, and lays out some—but not all—of the supporting evidence. In this case, a copy of the notice would also have gone to the World Anti-Doping Agency and the relevant governing bodies in track and field: USA Track and Field and the International Association of Athletics Federations. The notice indicates which rule or rules were allegedly violated, and the possible punishments. A coach or manager could face up to a lifetime ban for a first anti-doping infraction if the offense involves trafficking or administering banned substances. They may also receive a lifetime ban if they are found to have committed multiple separate doping offenses.

Lifetime bans, though, are rare. Cyclist Lance Armstrong received one, but his team manager, Johan Bruyneel, who was found to have helped orchestrate a years-long doping conspiracy, received a 10-year ban. And with the exception of the BALCO and U.S. Postal Service cycling team investigations—both of which involved law enforcement at some point—coaches typically escape punishment.

Precisely how much of USADA's case against Drummond stems from Gay's information is still unclear. Drummond can contest the allegations in a USADA notice before a three-person independent review board, which determines whether USADA has sufficient information to proceed with charges. If the notice is uncontested or the review board gives USADA the okay to proceed, it becomes a formal charge, which the accused can then fight in arbitration.

Drummond's lawsuit seeks to halt these proceedings, a tactic unsuccessfully tried earlier by Armstrong. In 2012, Armstrong filed a lawsuit in Texas attempting to stop USADA's disciplinary process. Armstrong's claim was not defamation, but that USADA had no authority to bring a doping case against him. A federal judge dismissed the case, ruling that the arbitration process in place for anti-doping investigations is robust and provides appropriate due process. Legal experts said a judge is unlikely to proceed with a case related to USADA's disciplinary procedures prior to the completion of the arbitration process.

But even if Drummond's suit is allowed to proceed, sports law experts say he will be hard-pressed to prove he was defamed, partly because he will likely be deemed a public figure, and will have to prove to a jury that Gay and Tygart intentionally lied about him. Armstrong, who fought a scorched earth legal battle, did not attempt a defamation claim, but "if [Armstrong's] lawyers thought a defamation claim had a chance," said Michael McCann, director of the Sports and Entertainment Law Institute at the University of New Hampshire, "I assume they would have included it. The fact that they didn't seems telling to me, and would seem to favor USADA in regards to Drummond."

A statement from USADA said the agency will ask for the lawsuit to be dismissed, and called it "baseless," and "an effort to circumvent the mandatory arbitration process established to protect the rights of all clean athletes."

Representatives for both Drummond and Gay declined further comment.

As ProPublica has reported, Gay told USADA investigators that Drummond referred him to Atlanta chiropractor Clayton Gibson—a fact Gibson confirmed—and that Gibson provided creams containing substances banned in track and field. Gay also told investigators that Drummond transported the creams for him from Oregon to Monaco for a training camp prior to the 2012 Olympics, where Drummond coached the U.S. 4x100 meter relay team.

In his complaint, Drummond said that other athletes he trusted gave him good reports about Gibson, and he named sprinter Marshevet Hooker as one such athlete. Drummond previously told ProPublica that Hooker was dating then-Baltimore Ravens running back Willis McGahee, and that she began seeing Gibson on McGahee's recommendation. Gibson claims to have numerous pro-athlete clients, and he has treated high profile NFL players, including safety Ed Reed, McGahee's former Ravens teammate.

Drummond's lawsuit lays out his version of the initial meeting he and Gay had with Gibson prior to the 2012 Olympic Trials. Gibson, he said, showed Gay anti-aging creams that he claimed were all natural, even though the labels said they contained the banned substances testosterone, human growth hormone, and insulin-like growth factor. Gibson told them that the labels were a marketing ploy for non-athletes and did not contain banned substances, the suit says. (As ProPublica reported earlier, the creams are sold by a company owned by Swiss chiropractor Erich Breitenmoser, who was unable to say what is actually in the creams.) In his complaint, Drummond said he suggested removing the labels to avoid misleading athletes. According to people with knowledge of Gay's statements to investigators, when the creams arrived in Monaco, the labels had been removed.

The lawsuit claims that when $9,000 worth of supplements and creams from Gibson arrived for Gay, Drummond "unequivocally recommended that Mr. Gay discard all products, including the creams, which Mr. Drummond did not himself recognize as safe and appropriate." According to people familiar with what Gay told USADA, the sprinter indicated that Drummond encouraged him to use the creams and transported them for him to Europe.

Last summer, before he failed the drug tests, Gay had the fastest 100-meter time in the world, and appeared to be the lone legitimate rival to Jamaican sprinter Usain Bolt for the upcoming world championships. Because Gay stopped competing immediately after he was notified of his failed tests, he will be eligible to race again starting next month. He recently returned the silver medal he won in the 4x100-meter relay at the 2012 London Olympics, a medal he once said "kept me from jumping off a bridge."