MOSCOW (Reuters) - A group of Russian sports stars has appealed to the International Olympic Committee to let athletes with no history of doping compete at the Rio Games in August, days ahead of a ruling on Russia's ban from world athletics.

Thirteen Olympic medalists and world champions signed a letter addressed to IOC head Thomas Bach saying it would be unfair if Russian track-and-field athletes with no record of using banned substances were not allowed to go to Rio.

"The fraud of dishonest people should not jeopardize the career of the other innocent fellow athletes and throw a stain on our country's reputation," they said in the letter, a copy of which was seen by Reuters.

"The right of any athlete who has never violated any of the existing rules to perform at the Olympic Games is inviolable."

Those signing the letter included Alexander Popov, a four-time Olympic champion swimmer, Olympic judo champion Tagir Khaibulaev and others from a range of summer and winter sports.

After being suspended by the International Association of Athletics Federations (IAAF) last year, Russia is trying to convince sports authorities it is serious about rooting out cheats and overhauling its anti-doping systems.

The IAAF will decide whether Russia has done enough to have the ban overturned at a meeting in Vienna on Friday.

But Russian sports officials say the IOC could still invite individual athletes to compete at the Games even if the IAAF rules to uphold Russia's suspension.

Russian Sports Minister Vitaly Mutko also wrote to IAAF head Sebastian Coe on Wednesday outlining the progress Russia has made reforming its disgraced athletics association, TASS news agency reported.

(Reporting by Jack Stubbs; Editing by Dmitry Solovyov and Hugh Lawson)