The CAS has published the reasoning behind its decision to uphold Legkov's appeal after he was initially stripped of his Olympic 50 kilometres gold medal and relay silver medal by the IOC.

The full 160-page verdict from the Lausanne-based body also casts doubt on elements of the testimony provided by former Moscow Laboratory director Grigory Rodchenkov, who has provided much of the evidence in the Russian doping cases.

In the decision on Alexander Zubkov, who lost his two Olympic bobsleigh gold medals he won at Sochi 2014 and who subsequently failed with his appeal, the CAS seem to confirm the existence of a doping scheme beyond any doubt.

CAS state in the reasoning on Zubkov that Rodchenkov's evidence, added to forensic findings showing sample-tampering, was enough to establish an anti-doping rule violation.

Legkov was one of 28 Russians cleared by the CAS prior to Pyeongchang 2018.

Zubkov was among the 11 whose sanctions were upheld.

The CAS ruled that athletes implicated in the doping system in operation at Sochi 2014 could only be found guilty of an anti-doping rule violation if it could be proved they were "personally and knowingly" involved.

Russian athletes who willingly participated in the sample-swapping scheme had to have either provided clean urine before the Games in order for it to be substituted or deliberately not fully closed the sample bottle.

The IOC had failed to demonstrate this was the case with Legkov, CAS said.

"It is insufficient merely to establish the existence of a general sample-swapping scheme; rather, the Panel must be comfortably satisfied that the athlete was personally and knowingly implicated in particular acts that formed part of, and facilitated the commission of, the substitution of his urine within that scheme," the CAS decision reads.

"In short, therefore, there is no direct evidence that establishes either that the athlete provided clean urine with the knowledge that this would be used for the purpose of urine substitution or that he did not fully close the sample bottles."

The CAS ruling on Legkov also claims the presence of "multiple T marks" and being named on the Duchess List alone - drawn up by Rodchenkov and consisting of athletes who supposedly had positive drugs tests destroyed or tampered with before and during Sochi 2014 - was insufficient to prove wrongdoing.

An athlete featuring on the Duchess List was substantial enough only when "viewed in conjunction with other relevant probative evidence".

The IOC's reasoned decision on the now-retired skier, which claimed Rodchenkov specifically recalled swapping Legkov's samples, was also disputed by the CAS.

"Dr Rodchenkov did not provide any particulars in his diary regarding that alleged swapping," CAS said.

"Accordingly, Dr. Rodchenkov’s statement is a bare assertion which is uncorroborated by any contemporaneous documentary evidence."

CAS said that as "none of the IOC's factual allegations had been proven" to its "comfortable satistfaction", the IOC had therefore "not discharged the burden of establishing that the athlete used a prohibited method for the purposes of Article 2.2 of the World Anti-Doping Agency Code".

"In particular, the panel concludes that the probative value of the circumstantial evidence is insufficient to overcome the absence of direct evidence that the athlete committed an anti-doping rule violation of use of a prohibited method," the ruling added.

The Panel were able to determine, however, that Zubkov's case met the required criteria for an anti-doping rule violation to be brought against the athlete.

CAS ruled his sample had "physiologically impossible" salt levels and that he provided clean urine before Sochi 2014 "for the purpose of enabling the subsequent sample swapping".

"His samples at the Games were in fact subsequently swapped, with salt being added to the substitute urine in an effort to conceal the existence of the substitution," the conclusion added.

The CAS decision on Legkov also seems to suggest the IOC's quickfire nature in handling all of the cases meant they were only able of proving some to the required standard.

The 28 Russians whose appeals were upheld had their results from Sochi 2014 reinstated.

The bans remained in place for the other 11 athletes, although it was ruled that a lifetime Olympic suspension was unenforceable and the group were consequently prevented only from competing at Pyeongchang 2018.

The IOC reacted furiously to the verdicts and claimed there was an "urgent need" to reform the CAS to ensure more consistency in their decisions.

It was initially thought that all 39 verdicts would be published in one go but the CAS confirmed today they will issue the remaining 37 in the coming weeks.

Many other world governing bodies are currently assessing whether to prosecute cases against individual athletes.

The reasoned decisions are expected to form the legal basis for these cases.