Insisting that he is running clean, Usain Bolt said on Thursday that the recent spate of doping scandals in athletics will damage the sport.
They won't affect his preparations for the upcoming world championships, however.
The world's fastest man stopped short of condemning Jamaican teammates Asafa Powell and Sherone Simpson or American rival Tyson Gay, whose failed doping tests have left the sport in turmoil ahead of the worlds in Moscow next month.
"Definitely it's going to set us back a little bit," Bolt said in London ahead of a Diamond League meet, his first competition in the city since his three gold medals at last year's Olympics. "But as a person I can't focus on this.
"I still have world championships, everyone is stepping up their game so I have to really focus on that. ... I am just trying to work hard, run fast and hopefully help people to forget what has happened, and just move on."
Bolt will run the 100 meters on Friday and the 4x100 relay on Saturday at the Olympic Stadium in a meet marking the anniversary of the start of the 2012 London Olympics.
In his first public comments since news of the high-profile doping cases broke, Bolt promised that he won't be the next sprint star to be embroiled in a scandal.
"I was made to inspire people and to run, and I was given the gift and that's what I do," the six-time Olympic champion said. "I am confident in myself and my team, the people I work with. And I know I am clean.
"So I'm just going to continue running, using my talent and just trying to improve the sport."
If the recent cases have cast doubt about Bolt's own integrity, the 100- and 200-meter world record-holder asked any skeptics to just check his record.
"If you were following me since 2002 you would know that I have been doing phenomenal things since I was 15," the 26-year-old Bolt said. "I was the youngest person to win the world juniors at 15. I ran the world junior (200) record 19.93 at (17) ... I have broken every record there is to break, in every event I have ever done.
"For me, I have proven myself since I was 15. ... I have shown everything throughout the years since I was always going to be great."
It was announced earlier this month that Powell and Simpson tested positive for the stimulant oxilofrone at Jamaica's national championships in June. Discus thrower Allison Randall and two other athletes also returned positives for banned substances at the same meet.
"I'm just sitting and waiting to see the results and what's what," Bolt said. "There's a lot things that hasn't been said and done yet."
Bolt said he has spoken only briefly via text message with Powell since the positive test was announced.
"I didn't want to bombard him with questions," Bolt said. "I told him, 'Sorry to hear what was going on.' And he said 'Yes, it's kind of rough, it's hard.'
"And I just told him to stay strong and stay focused, and hopefully everything will work out."
Powell was the last man to hold the 100-meter world record before Bolt broke it in 2008. He also helped the Jamaicans to the 4x100-meter relay gold medal at the 2008 Beijing Olympics.
In almost 20 minutes with reporters in London on Thursday, Bolt avoided any direct criticism of his fellow athletes.
"In life things happen, people make mistakes, mishaps happen," Bolt said in response to a question about doping sanctions.
Both Powell and Gay claim they failed doping tests because they trusted people they didn't know very well.
Bolt does not doubt his inner circle and was astounded by the suggestion he could inadvertently be given a banned supplement and test positive.
"What? I am clean," Bolt shot back while insisting he only takes vitamins and not supplements. "You have to be careful as an athlete what you do and what you ingest, the food you eat and stuff like that.
"But I am not worried because ... I have a great team around me."
Questions about the apparent leniency of two-year doping bans were sidestepped by Bolt.
"I can't determine how harsh the rules should be," he said.
Sprinter Kim Collins, who is also competing in the two-day London meet, accepts that every athlete is now under scrutiny, saying the wave of recent doping cases "leave a bad taste for all of us."
"Everyone is judged and I will be judged running fast at my age," said the 37-year-old Collins, a former 100-meter world champion from St. Kitts and Nevis.