Justin Gatlin, the world 100 metres champion, is at the centre of a new doping scandal after members of his team offered to illicitly supply performance-enhancing drugs.
Gatlin and his coach are now being investigated by sports and doping authorities after a Telegraph investigation uncovered how members of his entourage offered to provide prescriptions in a false name and smuggle the substances to America.
Undercover reporters visited Gatlin's Florida training camp where his coach, the former Olympic gold medallist Dennis Mitchell, and an athletics agent offered to supply and administer testosterone and human-growth hormone for an actor training for a film.
The products were to be provided via a doctor in Austria. The total fee for the project was US$250,000 (£187,000).
Mitchell and the agent, Robert Wagner, were also secretly recorded claiming that the use of banned substances in athletics was still widespread as they described how positive doping tests could be avoided.
In one meeting, the agent claimed that Gatlin had himself been taking performance enhancing drugs – which the sprinter has strenuously denied in a statement.
On Monday night, Gatlin's legal representatives announced that he had sacked his coach and revealed more than five years' worth of official drugs tests to show "he has never tested positive for any banned substance".
Gatlin's agent for the last 14 years, Renaldo Nehemiah, said that Wagner had worked for Gatlin on no more than two or three occasions and that the sprinter was not present when banned substances were discussed with the agent or coach.
Read more: Parents of Justin Gatlin leap to his defense
The revelations threaten to reignite the scandal of doping in sport just three years after Russia was said to have systematically doped its athletes. Gatlin himself has twice been banned for doping, in 2001 and 2006.
The Athletics Integrity Unit (AIU), which was set up by the International Association of Athletics Federations (IAAF) in the summer, and the US Anti-Doping Agency (USADA), said they had opened an investigation into the sprinter, the agent and the coach after being made aware of the Telegraph investigation.
A spokesman for the AIU said that the code of conduct applied to athletes and their support personnel and that "designer drugs" had "always been a challenge for the anti-doping movement".
A spokesman for the US Anti-Doping Agency said: "Investigations stemming from tips and whistleblowers play a critical role in anti-doping efforts. We are presently coordinating with the Athletics Integrity Unit in order to investigate these claims fully."
Lord Coe, the IAAF president, said: "These allegations are extremely serious and I know the independent Athletics Integrity Unit will investigate in accordance with its mandate."
Gatlin controversially beat Usain Bolt at the Jamaican world record holder's final competitive raceat the World Championships in London last summer. Gatlin was booed by the crowd, with some commentators unhappy that he was allowed to compete as a result of his chequered past.
Read more: Gatlin finally beats Bolt
The Telegraph began the undercover investigation in July after being told that specific agents and trainers were involved in administering and supplying drugs to athletes and that the regulators had failed to take action.
One of the individuals identified was Wagner, who boasted he had represented some of the biggest names in the sport, including Ben Johnson and high profile British athletes including Colin Jackson, the hurdler, and Dame Kelly Holmes, the Olympic gold medallist.
Johnson was banned for taking performance enhancing drugs in the Eighties and was stripped of his 100m gold at the 1988 Olympics. There is no suggestion that the other athletes have ever taken any banned substances.
Undercover reporters posed as representatives of a production company who were making a film about athletics. They said that they wanted to find people to train the star of the film, so that he could be in shape to play an athlete.
Wagner named a number of high profile people who he claimed would be willing to take part in the training plan. Wagner said that he had informed the IAAF integrity unit about his communication with undercover reporters in November.
"I wasn't involved in doping," he said. "Obviously I played along because I knew what was going on. I had to get them hooked."
When asked about his claims that his colleagues used banned substances he said: "I told her that to get the job."
He denied that he knew of Gatlin's use of performance enhancing drugs, saying: "I am not Justin Gatlin's agent, how would I know that?"
The agent suggested that both testosterone and human growth hormone might be useful to ensure that the actor got into shape quickly and that the prescription for the products could be acquired in his name and via a doctor who already supplied the products to him personally.
"I will have to give my name and get this, and get this through my prescription, right" said Wagner.
He boasted that using drugs was a "daily situation" and his "field of expertise".
He said: "I cannot tell you openly in front of five people that this is what we're always doing left and right. This is what track and field is about."
- By Claire Newell, Hayley Dixon, Daniel Foggo, Callum Adams, Luke Heighton