Thursday 12 May 2016 23:35, UK
The International Olympic Committee has called for "very detailed and very worrying" allegations of Russian state-sponsored doping at the Sochi 2014 Winter Olympics to be investigated immediately by the World Anti-doping Agency.
Hosts Russia topped the medal table in Sochi with 33 medals, 13 of them gold, but a New York Times report claims performance-enhancing drug use was rife and covered up.
Dr Grigory Rodchenkov, who was director of the country's anti-doping laboratory at the time, alleges urine samples tainted by performance-enhancing drugs were exchanged, through a wall, for clean urine collected months earlier.
"People are celebrating Olympic champion winners, but we are sitting crazy and replacing their urine," Dr Rodchenkov told the New York Times. "Can you imagine how Olympic sport is organised?"
WADA on Tuesday announced it would investigate allegations of doping at Sochi made in a CBS 60 Minutes documentary last Sunday. And the IOC called for further inquiries in response to the claims in the New York Times.
An IOC spokesman said: "These allegations are very detailed and very worrying and we ask the World Anti-Doping Agency to investigate immediately.
"The laboratory in Sochi was fully accredited by WADA. The IOC also relied on the work of its own international experts in the laboratory - the Games group.
"Additionally, to safeguard the excellence of the analytical work of the laboratory, 15 to 20 international experts from 10 WADA-accredited laboratories, including several laboratory directors supervised the activities of the lab.
"The organisation of the laboratory including the quality control system and chain of custody documentation was compliant with all international rules and regulations.
"A WADA independent observer team monitored all anti-doping activities during the Sochi Olympic Winter Games and produced a satisfactory report following the Games.
"Based on the findings of a WADA inquiry the IOC will not hesitate to act with its usual policy of zero tolerance for doping and defending the clean athletes."
The Russian Ministry of Sport on Thursday night described the allegations as "a major shock" and questioned Rodchenkov's motives.
A statement from the Russian Ministry of Sport read: "The allegations made by the former director of the laboratories came as a major shock to us.
"Considering that he was fired from his position for manipulating tests it is very likely that he has other motives.
"If these allegations have any factual substantiation, they should be handed over immediately to relevant anti-doping organisations for a full investigation."
Russia's track and field athletes are currently the subject of a suspension which places their participation in the Rio Olympics in doubt.
The ban was imposed following a WADA-commissioned independent report into allegations of drug use in athletics.
UK Anti-doping was subsequently commissioned to undertake drug testing in Russia and has uncovered just two incidences of doping, according to Russian sports minister Vitaly Mutko.
In making the comments, Mutko omitted adverse findings for meldonium, which was banned from January 1, 2016.
The Russian Ministry of Sport statement, responding to the New York Times allegations, added: "We have never claimed that we do not have doping problems and we acknowledge that changes are needed and we understand that we have to regain international community's trust for what we believe is a global issue.
"The only way that we can achieve this is through concrete steps proving our loyalty to clean and fair sport.
"We believe we have already proved Russia's commitment to fight doping by inviting international experts recommended by WADA to all key positions responsible for doping control and this guarantees independence and transparency of procedures.
"We have nothing to hide. And we will continue this work."