Yet Mr. McLaren suggested that the full extent of the cheating might never be known.
“It is impossible to know just how deep and how far back this conspiracy goes,” he said on Friday, calling the “immutable facts” of his report clear but far from comprehensive. “For years, international sports competitions have unknowingly been hijacked by the Russians.”
Mr. McLaren concluded last summer that Russia had orchestrated rampant doping dating back years that culminated in an elaborate urine-swapping operation at the 2014 Sochi Games, confirming what The New York Times reported in May.
But in the face of staunch denials from Russian officials and skepticism from sports authorities reluctant to punish the nation on his word, he and a team have continued their work these last five months.
Asked for their evidence, they zeroed in on the individuals who had enabled the cheating as well as those who had benefited from it, publishing on Friday 1,166 pieces of proof, including emails, documents and scientific and forensic analysis of doping samples.
As part of the inquiry, the team examined some 120 urine samples of Russian athletes from Sochi out of at least 250 that have been preserved since 2014. All the samples Mr. McLaren examined had been tampered with, he said, including those of 15 medalists — including winners of gold.
From the 2012 London Games, Mr. McLaren identified 15 medalists whose doping violations had been concealed. Ten of them have been stripped of their medals, the report said, after widespread retesting this year.
The names of most of the implicated athletes were redacted — they were referred to by unique sets of numbers — but their identities had been privately shared with relevant officials for each sport’s global governing body, Mr. McLaren said, emphasizing that it was not his job to issue penalties.
Outside of the Olympics, sports governing bodies have autonomy over disciplining athletes for violations like doping or manipulating samples.
Thomas Bach, the president of the I.O.C., said in a statement on Friday that the report’s findings demonstrated “a fundamental attack on the integrity of sport.” On Thursday, he had said that “any athlete who took part in such a sophisticated manipulation system” should be excluded from attending future Olympics in any capacity.
Mr. Bach said all urine samples retained from Russian athletes who competed in the 2014 Sochi Games would be re-examined, along with those from the 2012 London Games that have not yet been retested.
The I.O.C. has appointed two commissions in response to Mr. McLaren’s report. A team is expected to examine the Sochi doping samples for evidence of banned substances — though unlikely to find any if tainted urine was substituted — as well as other signs of tampering.
On Friday, Mr. Bach called Mr. McLaren to thank him for his work, which he previously had greeted with skepticism.
“It was a big change from the reaction in July,” Mr. McLaren said.
The Russian sports ministry said in a statement that it was studying the report “to formulate a constructive position,” denying the existence of any state-sponsored doping programs in sports and promising to “continue the fight against doping from the positions of ‘zero tolerance.’”
The ministry pledged its cooperation with global sports and antidoping authorities to improve Russia’s antidoping operations.
Mr. McLaren’s report described the lengths to which various branches of the Russian government went to shield the nation’s antidoping lab from scrutiny. In 2014, when World Anti-Doping Agency inspectors were due to make a surprise visit to the Moscow lab, personnel at the Ministry of Sport tipped the lab off to their trip after learning they had applied for visas.
The evidence also included crucial communications between Russia’s former deputy sports minister Yuri Nagornykh — who was dismissed amid scandal last summer — and Dr. Grigory Rodchenkov, the nation’s former antidoping lab director, who told The Times last spring exactly how he had helped top Russian athletes dope on state orders.
He described an operation out of a spy thriller in which he, with the guidance of sports officials and the help of members of the country’s intelligence service, broke into supposedly tamper-proof bottles every night to replace urine tainted by performance-enhancing drugs with clean urine collected months earlier.
Mr. Nagornykh and the sports ministry gave Dr. Rodchenkov explicit direction to cover up top athletes’ use of performance-enhancing steroids, according to emails and spreadsheets.
Mr. McLaren’s report and an accompanying searchable website of evidence leave little doubt that Russia’s doping program was among the most sophisticated in sports history, perhaps ranking only behind that of the East German regime.
Some felt it was worse after reading the details.
“Even in the darkest days of state-sponsored doping in the former East Bloc in the 1970s and 1980s, the organized drugging of athletes was not also propped up by the deliberate corruption of antidoping measures on such a shocking scale,” said Joseph de Pencier, chief executive of the Institute of National Anti-Doping Organisations, based in Germany.
He called for the I.O.C. to exclude Russia from the Olympics until it was “demonstrably free of the will to subvert the fundamental values and spirit of sport.”
The I.O.C. commissions’ work is expected to lay the foundation for disciplinary action against even more Russian Olympians, after a year in which dozens have been penalized and more than 100 barred from global competition.
Leading up to the report’s release on Friday, sports officials had braced themselves for the final set of facts with which the disciplinary authorities would be expected to work.
“I hope it’s all for nothing,” Gian-Franco Kasper, an I.O.C. executive and president of skiing’s global governing body, said during a smoke break in Switzerland this week in the middle of a full day of closed-door meetings with sports officials who were anticipating the McLaren report.
“For the winter sports federations, we’re in the middle of the season,” Mr. Kasper said. “We’re going to have to react immediately. In the middle of the competition, it’s not easy.”
Winter sports officials could encounter acute pressure similar to that faced by summer sports officials this year when they had about two weeks to rule on which Russian athletes could compete in Rio after Mr. McLaren’s report.
Russia is set to hold the world championships in bobsled and skeleton in Sochi in two months. American athletes have talked about boycotting that event as a show of dissatisfaction with sports officials’ handling of the Russian doping scandal. The governing body for those sports said on Friday that it would give “highest priority and urgency” to reacting to the new details.
On Thursday, less than 24 hours before the report’s publication, Mr. Bach repeated the Olympic committee’s guidance that sports federations freeze or terminate their preparations for hosting events in Russia.
But ahead of Friday, Mr. Bach had little idea what to expect. Mr. McLaren had closely guarded his findings, declining to share them earlier with Olympic officials as they requested; he instead waited to make the package public on Friday. He will be cooperating with the I.O.C. commissions going forward, he said.
One of the chief criticisms Russian officials and some global sports authorities made of Mr. McLaren’s initial work was that he had not heard Russia’s side of the story. In Friday’s report, he addressed that possible vulnerability, invoking his communications with Vitaly Smirnov, a former longtime Olympic official from Russia whom President Vladimir V. Putin appointed last summer to lead antidoping reform.
Vitaly Mutko, Russia’s former minister of sport, whom Mr. Putin recently elevated to deputy prime minister, did not accept Mr. McLaren’s request for a meeting, the report said.
Mr. Smirnov’s statements about reforming Russia, Mr. McLaren suggested on Friday, may be the most direct sort of admission he expects to receive that the “institutional conspiracy” he detailed took place. In setting his findings out, Mr. McLaren called for an end to infighting in global sports and unity in fighting cheating.
“Russia needs to get its act together to change the culture,” Olivier Niggli, director general of the World Anti-Doping Agency, said, echoing something Mr. Mutko himself acknowledged to The Times in July.
“Hopefully this will help the Russians themselves to accept the facts and take a positive attitude toward changing things rather than saying this is a plot from the West with no evidence,” Mr. Niggli said. “It’s in the public domain, and everybody can look at it.”