The men's 100 metres may have been rocked by a series of doping scandals but the event still has the ability to get the world watching, Donovan Bailey said on Wednesday.

Just before the World Athletics Championships in Moscow, the second-fastest man in history, Tyson Gay, and former world record-holder Asafa Powell of Jamaica both tested positive, sending shockwaves through the sport.

But Canada's Bailey, also a former world record-holder and Olympic gold medallist in 1996, said while there were great stars in other events, fans still hold their breath for the straight sprint showdown.

"The 100m will always be the blue riband event at any championships, so it's not taking away from any other event and it never has," said 45-year-old Bailey, who is in the Russian capital as a television pundit.

"There have been great milers, great pole vaulters, great stars in other events. But the world will always only stop for 10 seconds."

An indication of how much the event has been affected by doping down the years is revealed in the list of past world champions.

"Based on the published lists, my name and (current world champion Usain) Bolt's are the only previous champions who have never been associated with doping and I don't mind being on that list," said Bailey.

Bailey, who inspired Canada to Olympic 4x100m relay gold in 1996 in Atlanta, said that the presence and profile of Jamaican star Bolt more than made up for others who have fallen foul of drug testing.

Six-time Olympic gold medallist Bolt is now one of the most-recognised athletes on the planet and his showmanship has given a positive image for the sport.

But Bailey said he did not think too much of a burden was being placed on the 26-year-old Bolt's broad shoulders.

"No it's not too much responsibility. I've been there before," said Bailey, who was also born in Jamaica but whose family emigrated to Canada.

"Whether we like it or not it's our responsibility to compete cleanly and be an ambassador. Usain Bolt is doing an amazing job on and off the track."

With Gay now out of the picture Bailey does not see anyone else coming close to challenging Bolt, who can equal Carl Lewis's haul of eight world golds if he retains the 200m title and Jamaica win the 4x100m relay.

"Bolt has to keep challenging himself," said Bailey.

"And clearly the mark that has been set by him is the standard that all sprinters going forward have to aspire to achieve; they need to beat the clock not the man."

Bailey produced one of his finest performances at the 1997 worlds when, despite being injured and under pressure to withdraw, he lost by just a whisker to Maurice Greene.

He said that no sprinter was at currently at Bolt's level, the sprint star had benefited from progress in other areas.

"Right now there's a better surface, better shoe technology and design, sports- and event-specific training, planned nutrition programmes, better advanced therapy techniques," he added.

"From Jesse Owens to Usain Bolt, all these things have advanced and they're still getting better today."