|Russia was accused by the World Anti-Doping Agency (WADA) of state-sponsored doping for the 2014 Winter Olympics in Sochi. (AFP/FRANCK FIFE)|
The International Olympic Committee decided on Tuesday (Dec 5) to ban Russia from the 2018 Pyeongchang Winter Games, but to allow some Russian competitors still to take part as neutrals.
Here are key dates in the scandal:
Russia basks in a golden hue after topping the medals table at the Sochi Winter Games in the Black Sea resort, with 13 titles and 33 medals in total. President Vladimir Putin poses for photographs with many of the Russian winners.
German broadcaster ARD airs documentary alleging systematic doping in Russian athletics.
A week later, Russian athletics chief and the treasurer of world athletics body IAAF, Valentin Balakhnichev, and IAAF marketing consultant Pape Massata Diack, son of then-IAAF president Lamine Diack, step down.
The World Anti-Doping Agency (WADA) sets up an independent commission headed by its former chief, Dick Pound, to investigate the claims.
ARD airs a second documentary with new accusations aimed at Russian and Kenyan athletes based on a leaked IAAF database with details of 12,000 blood tests from 5,000 competitors which revealed "extraordinary" levels of doping.
WADA's report calls on Russia's track and field team to be banned from international competition, including from the 2016 Rio Olympics, until "state-sponsored" doping is eradicated. The IAAF suspends the Russian athletics team. WADA also suspends Russia's national anti-doping body, RUSADA, over non-compliance.
WADA's second report into doping and corruption is published. It says high-ranking IAAF officials must have known about the wide scope of doping.
The former head of Moscow's anti-doping laboratory, Grigory Rodchenkov, who is exiled in the United States, describes an organised doping campaign including at least 15 medallists from the Sochi Olympics, with the close involvement of the sports ministry and Russia's FSB security service, the successor to the KGB.
Three days after calling the claims "absurd", then Russian Sports Minister Vitaly Mutko changes tack, saying he is "ashamed and sorry".
Another ARD programme claims that Russian authorities have been covering up for coaches disgraced by the doping programme, directly pinpointing Mutko for his alleged involvement in the cover-up.
The IAAF Council unanimously votes to extend the ban on the Russian athletics federation, but offers an Olympic lifeline to athletes training outside the Russian system to compete in Rio as neutrals.
Barely two weeks before the Rio Games, Canadian law professor Richard McLaren releases a report for WADA which outlines rampant Russian state-run doping at the Sochi Olympics and other major sports events.
The investigation finds the FSB helped "the state-dictated failsafe system" carried out by the sports ministry and covering 30 sports.
WADA calls for Russia to be banned from the Rio Olympics.
IAAF clears only US-based long jumper Darya Klishina to compete in Rio, after 136 Russian athletes applied for exemption from the blanket ban.
After CAS dismisses the Russian appeal, the IOC executive decides that any Russian wanting to compete in Rio will have to prove that he or she was not involved in doping.
At Rio, around 270 Russians are cleared to compete, with 111 excluded.
Second part of McLaren Report published, alleging state-sponsored doping by the Russians between 2011 and 2015 with sample tampering at the 2012 London Olympics and Sochi 2014.
Twenty-eight Russians competing in Sochi are implicated in cheating by McLaren.
At the IOC's Congress in Lima to award the 2024 Summer Olympics to Paris and 2028 Games to Los Angeles, 17 national anti-doping agencies including the United States, France, Germany and Britain demand Russia's exclusion from Pyeongchang, calling it "one of the biggest doping scandals in sporting history".
President Putin warns of Russian "humiliation" and serious harm to the Olympic movement if the country is forced to compete under a neutral flag or excluded altogether.
IOC comes down hard on Russian cheats, stripping Alexander Legkov of his Sochi 50-kilometre cross country gold medal and banning him for life.
In the space of one month the IOC dishes out similar sanctions to 25 Russians from Sochi Games. Russia is stripped of four 2014 titles, and a third of their 33 medals, including the two titles won by their Sochi flag carrier, bobsleigh star Alexander Zubkov.
Mutko, now Russia's deputy prime minister, uses a speech before the draw for the 2018 World Cup that Russia will host to slam doping allegations as "an attempt to create an image of an axis of evil".
He says: "This is all because we are such a great sport superpower."
IOC bans the Russian Olympic Committee from the 2018 Winter Games but says clean Russian athletes will still be able to take part as independent competitors "under the Olympic flag".
Mutko receives a lifetime Olympic ban for his involvement in Russian doping, raising questions as to whether he can continue in his role as head of the organising committee for next year's World Cup.