The International Olympic Committee (IOC) said that a new report on state-sponsored doping in Russia had revealed "a fundamental attack on the integrity of the Olympic Games and on sport in general".
In a statement, it pledged to re-test all Russian competitors' samples from the 2014 Winter Games in Russia, and IOC President Thomas Bach told reporters that the IOC would now also test all the samples of the Russians who took part in the 2012 London Olympics.
"Following Professor (Richard) McLaren's findings, I have also today extended the mandate of the disciplinary commission to test all samples of all Russian athletes having participated in the Olympic Games London 2012," Bach said.
The second and final part of an independent report by Canadian lawyer Richard McLaren for the World Anti-Doping Agency (WADA) provided evidence that more than 1,000 Russian athletes competing in summer, winter and Paralympic sport were involved in or benefited from a conspiracy to hide positive drug tests.
It said there had been a systematic cover-up since at least 2011, which was refined at the 2012 Olympics, 2013 world athletics championships and 2014 Sochi Winter Olympics, and that more than 30 sports, including soccer, were involved in concealing positive doping samples.
The IOC say a report on Russian doping had revealed an "attack on the integrity of the Olympics"— RTÉ Sport (@RTEsport) December 9, 2016
The IOC said it would go beyond McLaren's mandate by re-analysing all 254 urine samples collected from Russian athletes at the Winter Games that Russia hosted in Sochi in 2014.
It said 63 blood samples collected from Russian athletes at those Games had been re-analysed and were negative.
The IOC, which opposed a blanket ban on Russia at the Rio de Janeiro Olympics but has asked international federations not to hold events there, had already set up two commissions to investigate the findings of McLaren's first report in July.
One, headed by former Swiss president Samuel Schmid, will look at the "institutional conspiracy" while the second, headed by IOC member Denis Oswald, will address the question of doping and manipulation of Russian athletes' samples.
But athletes and anti-doping bodies have accused the IOC of going soft on Russia.
"How much more information do we need to receive before enough is enough?"," two-time Olympic hurdler Jeff Porter, chair of the USA Track & Field (USATF) Athletics Advisory Committee, said.
"I am tired of the bureaucratic bullshit these organisations are playing, trying to appeal to their friends in Moscow. I want to see some action on part of the part of the IOC ... if they want to even remotely restore faith in the Olympic Movement."
Sport Ireland chief executive John Treacy believes the powers of WADA need to be strengthened to allow for the sanctioning of countries which are not fulfilling their anti-doping mandate.
"We can't tolerate countries, like Russia, that turn a blind eye to doping infractions and actually help cover it up,” he insisted.
“And there must be sanctions for them and that's the key piece. There must be a penalty on countries, like Russia, that don't comply."