The World Anti-Doping Agency's Athlete Committee has expressed disappointment over the decision by sport's highest court CAS to reinstate the medals and results of 28 Russians at the 2014 Winter Games, calling it "a massive setback for clean sport".
The Court of Arbitration for Sport on Thursday also overturned doping bans on the athletes imposed by the IOC following an investigation into alleged systematic doping at the Sochi Olympics which Russia hosted four years ago.
The WADA Athlete Committee, chaired by Canadian cross-country skier Beckie Scott, condemned the CAS ruling, which said there was insufficient evidence of anti-doping violations against the Russian athletes.
"We share the distress, uncertainty and frustration expressed by many athletes on the news of this ruling and believe this decision to be a massive setback for clean sport," the committee said in a statement on Tuesday.
"We stand by and renew our call (made 9 August 2017, London, UK) for 'the Court of Arbitration for Sport (CAS) to improve and strengthen its independence and continually strive to increase the quality of its arbitrators'".
The International Olympic Committee has refused to invite the 32 cleared Russians to this month's Pyeongchang Winter Games, noting there was evidence about the athletes that had not been available to the IOC commission that had investigated them.
The IOC has banned Russia from the Pyeongchang Games over its "unprecedented systematic manipulation" of the anti-doping system, although individual Russian athletes can compete as neutrals if they meet stringent IOC criteria.
"We cannot lose sight of the extent nor the scale of the efforts that Russian authorities and athletes engaged in to cheat the anti-doping system," the WADA Athlete Committee added. "Thus, we call for stronger leadership from sport to protect clean athletes and their right to doping-free sport."
Russia has repeatedly denied state involvement in doping.
CAS said 32 Russian athletes had appealed against their exclusion by the IOC from the Pyeongchang Olympics.
They include multiple Olympic champion speed skater Viktor Ahn and biathlon gold medallist Anton Shipulin.
CAS said the hearing was likely to take place on Wednesday, two days before the opening ceremony of the Games.
The IOC, which has cleared 169 Russians to compete at Pyeongchang, said that "not being sanctioned does not automatically confer the privilege of an invitation".
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)