GENEVA (AP) — In a blow to the credibility of Russia's denials that it operated state-backed Olympic doping, an IOC judging panel has endorsed a key whistleblower and the investigator who exposed the plot.

Orchestrated cheating at the 2014 Sochi Winter Games was "a conspiracy which infected and subverted the Olympic Games in the worst possible manner," an International Olympic Committee commission prosecuting a slew of Russian cases said on Monday.

Former Moscow and Sochi laboratory director Grigory Rodchenkov was a "truthful witness," the panel said in publishing its first detailed verdict on the same day it sanctioned five more Russian athletes to bring the total to 19.

Rodchenkov is living in the United States under FBI protection as a cooperating witness.

The IOC panel, chaired by Denis Oswald, agreed that investigator Richard McLaren — appointed by the World Anti-Doping Agency to verify Rodchenkov's claims to American media in May 2016 — proved the existence of a doping conspiracy beyond reasonable doubt.

The public vindication of Rodchenkov and McLaren, each repeatedly denounced by state authorities in Russia, will fuel speculation that the IOC executive board meeting next Tuesday should ban Russia's team from the Pyeongchang Olympics.

Medals in biathlon, bobsled, cross-country skiing, speedskating and skeleton have been stripped by the IOC, and Russia was knocked off the top of the medals table last week in a previous round of disqualifications.

The first athlete disqualified four weeks ago was Alexander Legkov, a cross-country skier who won the men's 50-kilometer gold and 4x10-kilometer relay silver.

The full verdict in his Oct. 30 case was published on Monday to reveal how strongly a judging panel of three IOC members believed the evidence first outlined last year of urine sample swaps and tampered bottles in the Sochi laboratory.

A 46-page document confirmed the panel "is more than comfortably satisfied that the evidence establishes that a scheme of sample-swapping as described in the McLaren Report and the affidavit of Dr. Rodchenkov was indeed in place and implemented in Sochi."

The ruling stopped short of joining the two men in accusing Russian government agencies, including the sports ministry and FSB security service, of complicity.

Still, this was a "sophisticated" system in place and was compared to a Swiss watch by the three-man panel, comprising two from Switzerland and one from Spain.

"(I)t was a very fine mechanism where many people had a role to play," the verdict in Legkov's case stated.

A final IOC judgment on whether the Russian state ultimately corrupted the Winter Games that cost $51 billion to prepare for and stage should come next week.

A separate commission chaired by a former president of Switzerland, Samuel Schmid, will give the IOC board its findings ahead of the Dec. 5 meeting to decide on punishing Russia.

The latest guilty verdicts announced on Monday involved Aleksei Negodailo and Dmitrii Trunenkov, members of the gold medal-winning four-man bobsled; Yana Romanova, the silver medalist in the 4x6-kilometer women's biathlon relay; Olga Vilukhina, the silver medalist in the same relay and 7.5-kilometer biathlon; and Sergei Chudinov, who was fifth in skeleton.

The Russian Bobsleigh Federation said in a statement the decisions were "the height of injustice" that lacked legal basis, and promised to contest them.

The appeals route for Russian athletes is the Court of Arbitration for Sport in the IOC's home city of Lausanne, Switzerland.

Trunenkov was already serving a four-year ban, backdated to April 2016, for a separate doping offense just before he retired.

Another member of the four-man team, Alexander Zubkov, was disqualified on Friday and stripped of his golds in the two-man and four-man. That meant Alexey Voyevoda, who won both golds with Zubkov, was also stripped of the medals. His case was considered by the IOC panel last Thursday.

A third member of the women's biathlon relay, Olga Zaitseva, had her hearing last week.

All disqualified athletes are also banned from the Olympics for life.

If the 2014 medals are reallocated, the four-man bobsled gold could go to Latvia. The United States could improve to silver, and a fourth-placed Russian team could receive the bronze.

In women's biathlon, Vilukhina's silver could pass to Vita Semerenko of Ukraine, and Karin Oberhofer of Italy could be promoted to bronze. The women's relay could see Norway could move up to silver and the Czech Republic get bronze.

Legkov was among athletes on the "Duchess List" — named for a fast-acting cocktail of steroids dissolved in alcohol and used as a mouthwash — who were protected by the doping system. Their clean urine was stored to be swapped in for tainted samples during the games.

Rodchenkov alleged swaps were done through a mouse hole in a lab room with FSB officers who worked out how to break into tamper-proof bottles. Scratches and marks on the glass were crucial evidence in Legkov's case.

"Whatever his motivation may be and whichever wrongdoing he may have committed in the past," the IOC panel said, "Dr. Rodchenkov was telling the truth when he provided explanations of the cover-up scheme that he managed."