Michael Johnson has rubbished claims from Justin Gatlin's coach Trevor Graham that the sprinter's failed drugs test was a case of deliberate sabotage.
Johnson says Gatlin was taking a risk working with his coach
Graham said an aggrieved masseur rubbed testosterone cream into Gatlin's legs believing the sprinter had him sacked.
But BBC pundit Johnson said Graham could not be taken seriously as several of his clients were serving drugs bans.
The US track legend wrote in the Daily Telegaph: "It's a new twist on an old excuse. Graham has no credibility."
Olympic and world 100m champion Gatlin, 24, has protested his innocence after announcing that he had tested positive at the Kansas Relays in April.
Even if Gatlin is innocent, he will be suspected forever and will see the danger of his continued association with Graham
He faces a lifetime ban for a second offence following a positive test for an amphetamine at the 2001 US Junior Championships which was later overturned but not annulled.
He should learn his fate within a week in a hearing before the United States Anti-doping Agency (USADA).
However, Graham is insistent his athlete is the victim of sabotage.
He told the Washington Post: "We know who the person is who actually did this.
"We are trying to make sure we can prove his innocence, and we hope this individual has the guts to come forward and say he did it."
But Johnson, a five-time Olympic gold medallist, wrote: "Graham has had several athletes who have tested positive or been banned from track and field.
Gatlin denies knowingly taking performance-enhancing substances
"Yet Gatlin has continued his association with Graham knowing it would probably taint him.
"Even if Gatlin is innocent, he will be suspected forever and is about to see the danger of his continued association with Graham."
Graham, who also coached the disgraced former world record holder Tim Montgomery, was the whistle-blower who launched the Balco steroid investigation in California.
He sent in the syringe to the authorities that sparked the scandal that rocked American athletics.
And Johnson, a nine-time world champion, said: "I was always disappointed that more people did not ask the question: where did he get the syringe from?"
Gatlin should be banned for life unless he can quickly come up with proof that he did not knowingly take a banned substance
The world 200m and 400m record holder added: "With a confirmed A and B sample... Gatlin should be banned for life unless he can quickly come up with proof that he did not knowingly take a banned substance.
"Circumstantial evidence produced by Gatlin, his coach and his lawyers that someone else is responsible should not be nearly enough.
"Graham should also be banned for life due to his involvement with an alarming number of athletes who have tested positive while training under him.
"Unfortunately, there is no rule in place to deal with coaches like him. And until there is, we might continue to see athletes cheating and damaging the sport."
Athletics' governing body the IAAF on Monday re-iterated its policy of an athlete's "strict liability".
The sport's been dragged through the mud again
A spokesman said: "Whatever is found in an athlete's body when tested is his or her responsibility alone.
"We have been advising athletes for many years now of this strict liability policy and encouraged them to be very cautious when receiving any form of treatment."
Marathon world record holder Paula Radcliffe believes athletics's image has again been tarnished by the Gatlin case but acknowledges that the sport has to accept the bad publicity surrounding such high profile cases in the ongoing battle to get rid of drug use.
"The sport's been dragged through the mud again," she said. "But, in the end, it is necessary if we are going to weed out and catch the drug cheats."