Rio de Janeiro, (AFP/PTI) Usain Bolt will launch an audacious bid for three Olympic sprint gold medals for an unprecendented third time as the perfect antidote to a year of turmoil in his drug-tainted sport.

Track and field has been dragged through the ringer since Sebastian Coe took over as president of the International Association of Athletics Federations (IAAF) in Beijing last August on a "zero-tolerance" anti-doping mandate.

Widespread corruption at the heart of the IAAF, involving Coe's disgraced predecessor Lamine Diack, was linked to shocking levels of institutionalised doping in Russia, one of track and field's powerhouses.

In November, the IAAF issued a blanket ban of Russia's track and field team over that state-sponsored doping, ruling that only US-based long jumper Darya Klishina was eligible to compete at the Rio Games, which start on August 5.

The Court of Arbitration for Sport (CAS) rejected a wider appeal by 67 track and field athletes including treble Olympic gold-chasing pole vault tsarina Yelena Isinbayeva, world 110m hurdles champion Sergey Shubenkov and world high jump champion Mariya Kuchina.

Whistleblower Yuliya Stepanova, the Russian 800m runner who lifted the lid on systematic doping fraud in her country, had been hoping to compete after being accepted by the IAAF as a neutral.

But Games organisers, the International Olympic Committee (IOC), said the Olympic Charter does not allow such a gesture even if they have invited Stepanova, who dubbed the decision "unfair", and her husband to Rio as guests.

One supporter of the IAAF's blanket ban on Russia is Bolt, the six-time Olympic gold medallist who is also world record holder in the 100, 200 and 4x100m relay.

"This will scare a lot of people, or send a strong message that the sport is serious about cleaning up," Bolt said.

"It's sad, but rules are rules. I don't make the rules, I don't make the decisions. I just have to go along with it. If you feel like banning the whole team is the right action, then I'm all for it.