London - Disgraced sprinter Ben Johnson is the face of a new anti-doping campaign.
The Canadian was stripped of his Olympic gold medal and world record in the 100m at the 1988 Seoul Games after testing positive for steroids.
After a two-year suspension, he received a lifetime ban in 1993 for a second positive doping test.
Now he is promoting an anti-doping campaign, Pure Sport, which has been launched by a sportswear company.
The campaign's backers say Johnson will ask sports fans to sign a petition demanding action to "improve the waning credibility of world sport," while demanding a truth-and-reconciliation process across sport.
Johnson will take his message to the Olympic Stadium in Seoul on September 24 — the 25th anniversary of the race where his reputation was shattered.