The International Olympic Committee rejected a request on Monday to invite 15 Russians to the Pyeongchang Winter Games just days after the athletes' doping bans were overturned by the Court of Arbitration for Sport.
The 13 active athletes and two retired athletes working in support roles were among 28 athletes whose bans were overturned by CAS on Thursday. The ban on 11 other Russians was upheld.
Russia Prime Minister Dmitry Medvedev denounced the IOC move as "shameful."
"This decision is unfair, unlawful, amoral and politically charged," Medvedev said on Facebook.
The IOC said as-yet unpublished new evidence — not examined in the CAS process — gave rise to new doping suspicions about the 15 Russians. The Kremlin argued the CAS decision meant the 15 should be treated as clean.
"We very much regret it. We expected that the CAS decision would dispel all suspicions against the athletes," Russian President Vladimir Putin's spokesman Dmitry Peskov said. "We're convinced that the CAS ruling has proved that such suspicions had no grounds."
In a statement on Monday, the IOC said part of its ruling was because "the full reasoning for these decisions had not been made public" by CAS.
"The decision of the CAS had not lifted the suspicion of doping, or given the panel sufficient confidence to recommend ... those 13 athletes could be considered as clean."
The IOC said the two coaches "should not be considered for an invitation" because of previous evidence available to the IOC.
The IOC added it had "additional elements and/or evidence" that included "traces of prohibited substances and evidence of steroid profile manipulation." It said this raised questions about the "integrity of these athletes."
Medvedev, meanwhile, argued the IOC "has trampled on the Olympic Charter and elementary principles of law" by refusing to invite the Russians who had been exonerated by CAS.
"This decision has little in common with sports, its goal is to do political damage to Russia," he said.
The IOC did not name the athletes, but Russian officials have said they include two gold-medal winners from the 2014 Sochi Olympics — cross-country skier Alexander Legkov and skeleton racer Alexander Tretiakov. They join dozens of other Russians who haven't been convicted of any doping offences but failed to pass the IOC vetting for an invitation.
The ruling by the sports court was a blow to the IOC and has shifted some of the focus away from Friday's opening of the games in frigid South Korea with about 3,000 athletes participating.
Speaking at the Olympic village, IOC President Thomas Bach repeated his disquiet over the CAS ruling and said on Monday an appeal was possible.
"We are extremely disappointed with this CAS decision," Bach said. "We will clearly review it. If we can appeal it, we will appeal it."
The Lausanne-based IOC could file that appeal with Switzerland's supreme court. However, the IOC says any appeal first requires seeing the reasoning of the judgments. CAS has said those might not be ready until the end of the month.
"The IOC, we would never have expected this," Bach said as uncertainty lingers over the Russian athletes. "We feel that this decision shows the urgent need for reforms in the internal structure of CAS."
"We only know about the reasons from a very few sentences in a press release."
John Coates, an IOC member and also the president of the International Council of Arbitration for Sport, tried to assure Bach the judicial reasoning would be forthcoming.
Russian officials and athletes have said they're also planning more legal action.
The IOC has invited 169 Russians to compete in Pyeongchang as "Olympic Athletes from Russia" under a neutral flag, but has said it reserves the right to review and appeal the CAS decision.