The head of the BALCO lab at the centre of a global steroid scandal claims he witnessed track star Marion Jones using steroids.
Victor Conte said in a television interview that Jones received illegal performance-enhancing drugs before winning five medals at the Sydney Olympics.
ABC television aired a portion of an interview with Conte in which he claimed not only to have supplied Jones with several banned drugs but also instructed her how to use them and watched as she injected herself in the leg.
"She did the injection with me sitting right there next to her, right in front of me," Conte said.
Asked in the interview if Jones was a drug cheat, Conte replied, "Without a doubt."
The full interview is scheduled to be broadcast on the American news show "20-20".
Jones, who has steadfastly denied any wrongdoing, won three gold medals and two bronze medals at Sydney but struggled this year simply to qualify for the Athens Games.
Jones has never failed a drug test but that means little. The US Anti-Doping Agency (USADA) fingered Conte's BALCO labs as the source of the previously undetectable designer steriod tetrahydrogestrinone (THG).
"It's like taking candy from a baby," Conte said of eluding dope tests, according to a story on the ABC News website.
Conte said he supplied Jones with a variety of banned drugs from August of 2000 through September of 2001, including EPO, human growth hormone, insulin and "the clear", a form of THG.
The San Jose Mercury News reported in May that Conte named Jones to federal investigators as one of 27 athletes he supplied with illegal drugs. Lawyers for Conte denied at that time that Conte named any athletes who received drugs.
Jones' lawyers have argued that Conte cannot be believed because of his role in a scandal which has rocked athletics and cast a shadow over baseball.
"Mr. Conte's statements have been wildly contradictory while Marion Jones has steadfastly maintained her position throughout - she has never, ever, used performance enhancing drugs," Jones attorney Rich Nichols said in a statement.
Conte, BALCO vice president James Valente, athletics coach Remy Korchemny and Greg Anderson, persoal trainer for baseball star Barry Bonds, face charges of steroid distribution. All have pleaded not guilty.
The BALCO trial, which featured testimony from several top athletes a year ago, is likely to begin in March, when Bonds will be preparing for a season in which he will likely pass Babe Ruth to become second on the all-time home run list.
Conte told ABC he provided steroids to Anderson but had no specific knowledge of Bonds using the drugs, the Chicago Tribune reported.
Jones, like Bonds, has never faced charges of taking illegal drugs, although she was the subject of a major USADA investigation.
While not in the televised material, the ABC website story said Conte admitted producing custom-made doping plans for Jones, world 100-metre record holder Tim Montgomery and admitted drugs cheat Kelli White.
Conte said his program for Montgomery "included illegal activity" and said his record was as legitimate as any prior 100m mark, hinting that he considers prior world marks as being achieved with the aid of banned substances.
According to USADA, 10 athletes have been sanctioned for testing positive for THG or modafinil, two of the drugs USADA believes are linked to BALCO.
Sprinters White and Alvin Harrison were banned for using THG and other drugs not after positive tests but on the basis of materials gleaned in the BALCO grand jury investigation.
New York Yankees baseball slugger Jason Giambi and his brother Jeremy were named in a San Francisco Chronicle story today as having testified to taking performance-enahncing drugs from BALCO.
