The anti-doping and athletics authorities are investigating newspaper allegations that members of controversial American sprinter Justin Gatlin’s entourage offered to supply performance-enhancing drugs.
Gatlin, 35, who has served two doping bans in his career, is the world 100 metres champion, having beaten Usain Bolt to gold in London in August.
Here, we take a look at the key questions surrounding the case:
Undercover reporters from the Daily Telegraph filmed Gatlin’s coach Dennis Mitchell and another member of the American sprinter’s entourage, athletics agent Robert Wagner, allegedly offering to obtain banned drugs for an actor training for a film. According to the newspaper, its reporters visited Gatlin’s Florida training camp and the pair offered to obtain and administer human growth hormone and testosterone for 250,000 US dollars (£187,000). The drugs, it is claimed in the report, would have been sourced from a doctor in Austria. Mitchell and Wagner were also secretly recorded claiming that doping is still widespread in the sport.
Mitchell, 51, won Olympic 4x100m gold in 1992 and two sprint relay two titles before being handed a drug ban in 1998 for testing positive for testosterone. His defence of having drunk five bottles of beer and having sex with his wife at least four times did not wash with world governing body the International Association of Athletics Federations. He started coaching Gatlin in 2011 and was the United States relay coach from 2014-17. Austrian Wagner is described in the Telegraph’s reports as Gatlin’s "race track agent". He is not Gatlin’s chief representative, who is Renaldo Nehemiah, who said Wagner had worked for Gatlin on only two or three occasions.
Gatlin is a highly controversial figure in athletics and is used to, if not happy with, his role as the sport’s pantomime villain. He has twice served doping bans, first in 2001 for amphetamines which he put down to attention deficit disorder medication he had been taking since childhood, and in 2006 for testosterone, which was blamed on testosterone cream being rubbed into his body without his knowledge by a massage therapist. He has always denied deliberately doping. And it is important to stress these latest allegations are not against him directly. There is no indication of wrongdoing on his part.
He has sacked Mitchell as his coach, saying he was "shocked and surprised" by the allegations against him. He also said in a statement he was not and had not used performance-enhancing drugs, and threatened legal action against anyone who claimed otherwise.
Both have strenuously denied committing any offences relating to the newspaper investigation, with Wagner claiming the comments he made were not true.
The United States Anti-Doping Agency (USADA) and the Athletics Integrity Unit (AIU), the new independent body set up by the IAAF to oversee all anti-doping matters in the sport, are investigating the allegations. IAAF president Lord Coe has described the claims as "extremely serious". They are certainly a blow to the credibility of a sport which is still struggling to emerge from the shadow of scandal.