|World Athletics Championships|
|Venue: Beijing National Stadium, China Dates: 22-30 August|
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Double world silver medallist Justin Gatlin "has apologised" for his previous doping offences, says the sprinter's agent Renaldo Nehemiah.
Gatlin, who has served two drug bans, has been criticised by some for not showing remorse for his misdemeanours.
But the Guardian has reported it has seen a letter from the American, 33, sent to the sport's governing body, the IAAF, apologising for his past actions.
Nehemiah said: "What is he supposed to do, go to every country and say sorry?"
Gatlin, the world's dominant sprinter coming into the World Championships, finished second behind Usain Bolt in the 100m and 200m in Beijing in a battle which was regarded in some quarters as a showdown between good and bad.
But his agent Nehemiah said: "When people say he never apologised, I say: 'You haven't done your homework.' And the IAAF, who know this, have never come out and said anything, which I am very sad about. Justin has apologised."
After winning the 100m and 200m world double at Helsinki 2005, the former world champion then tested positive for testosterone in 2006. He served a four-year ban that had been twice reduced from a lifetime and eight years.
Nehemiah added: "I have always said to Usada [United States Anti-Doping Agency] and Wada [World Anti-Doping Agency]: Come and test us, day or night.
"That's all we can do, make ourselves available and, if that's not good enough for people, that's just the world we live in."