Kelly Sotherton believes clean athletes will "definitely" lose out to drugs cheats at next year's Olympics.
Sotherton and Gardener have both lost out to drugs cheats
The British heptathlete told BBC Radio 5 Live Sport that cheats get away with it and likened doping to stealing.
She was reacting to a BBC Sport report that revealed the test for human growth hormone (HGH) was almost useless.
"As far as I am concerned, that is like telling athletes in all sports that they can take HGH at the next Olympics and get away with it," she said.
"I have already competed against somebody who cheated before. The girl (Lyudmila Blonska) who won silver at the world championships came back after serving a ban.
"So I know what it's like to lose a medal to somebody who has been banned.
Athletes have been massively exploiting HGH for a number of years
"I am training very hard at the moment. I just hope that everybody else in my event is training equally hard without the aid of drugs."
Sotherton, 31, who had to settle for a bronze medal behind Blonska in Osaka, called on anti-doping authorities around the world to catch up with the cheats and conduct more tests.
"If everybody else was as strict about drugs as we are in this country, I am sure a lot more cheats would be caught," she added.
Sotherton's call to arms was echoed by former Great Britain team-mate Jason Gardener.
The 32-year-old sprinter retired from athletics at the end of the summer after a long and successful career that could have been even more successful if all of his rivals had been playing fair.
Blonska returned from a steroids ban to win silver in Osaka
"I remember missing out on a spot in the 100m final at the 2004 Olympics by one place only to discover, a few months later, that athletes who made it have tested positive," said Gardener, who would go on to win a gold in the 4x100m relay days later.
"To make that final would have been a real achievement for me, particularly as I had just come back from surgery.
"And then a year later, at the world championships in Helsinki, I missed out on a place in the final by one one-hundredth of a second only for Justin Gatlin and Aziz Zakari, who were in my race, to then fail tests. And they're just the ones we know about."
Gardener, who started his career by winning an individual silver and relay gold at the world junior championships in 1994, told BBC Sport it was "common knowledge" that some athletes were using HGH without any fear of being caught.
"Athletes have been massively exploiting the use of HGH for a number of years," he said.
"They use it because you can recover from training a lot quicker - this is the key because it means more training. You can get much stronger, fitter and faster.
"The sooner we have a good test to detect it the better."
Gardener admitted that recent doping cases such as Gatlin's and the dramatic fall of Marion Jones have ruined the sport's reputation but he was adamant that athletics could recover.
"It's going to be very difficult but we must support what the anti-doping agencies are doing because they really are trying to level the playing field and make this sport fairer," he said.
"I think it's definitely a good idea to increase the bans from two years to four. In fact, I'm in favour of life-time bans."