World Anti-Doping Agency (WADA) President Sir Craig Reedie is "very disturbed" by the latest widespread athletics doping allegations which have emerged, vowing to immediately hand them over to the WADA Independent Commission for further investigation.
It comes after International Association of Athletics Federation (IAAF) data showing the results of 12,359 blood tests given by more than 5,000 athletes over an 11-year period starting in 2001 have been leaked to German TV station ARD and the Sunday Times in London.
More than 800 athletes had given blood samples that were "highly suggestive" of doping or "abnormal", it was reported, with a third of medals in endurance events at the Olympics and World Championships over the period, consisting of 55 golds at events including the London 2012 Olympic Games, won by athletes who submitted such samples.
Speaking here during the third day of the International Olympic Committee (IOC) Session, Sir Craig admitted to being worried by the scale of the allegations but vowed to maintain an "innocent until proven guilty" approach.
“WADA is very disturbed by these new allegations that have been raised by ARD; which will, once again, shake the foundation of clean athletes worldwide,” he added in a statement.
“Given the nature of these allegations, which are an extension to those that were raised by ARD’s December 2014 documentary, they will immediately be handed over to WADA’s Independent Commission for further investigation.
“These allegations require swift and close scrutiny to determine whether there have in fact been breaches under the World Anti-Doping Code and, if so, what actions are required to be taken by WADA and/or other bodies.
“As always, WADA is committed to doing what’s necessary to ensure a level playing field for clean athletes of the world.”
This latest report follows a previous ARD documentary last December alleging "systematic doping" within the Russian athletics team as well as a list of athletes with allegedly suspect values.
An Independent Commission, chaired by WADA’s founding President, Dick Pound was subsequently set up investigate the validity of the allegations.
The Independent Commission is scheduled to deliver its report to WADA’s President by the autumn, Sir Craig said, although it now appears possible this time could be extended in order to take in the new allegations.
The IAAF claimed in a statement the allegations its database of private and confidential medical data had been "obtained without consent." It reserved the right "to take any follow up action necessary to protect the rights of the IAAF and its athletes".
IAAF vice-president Sergey Bubka, also attending the IOC Session here, said: "There will be zero tolerance, this is clear.
"The IAAF is a very strong leader in the fight against doping.
"We will not stop the fight. If we need to change rules and regulations we will do it."
Bubka, the 1988 Olympic pole vault champion, is standing to replace Lamine Diack as President of the IAAF when she Senegalese steps down after 16 years.
Bubka's rival, the double Olympic 1500 metres gold medallist Sebastian Coe, also promised the IAAF would take the allegations seriously.
"In response to today's media reports, I know that the IAAF takes these allegations extremely seriously and it will issue a robust and detailed response to them and continue to work closely, as it has always done, with WADA," Coe, the former chairman of London 2012, said on Twitter.
Svein Arne Hansen, President of European Athletics, also expressed his dismay at the latest claims to hit the sport.
"The allegations of suspected widespread doping in top-level athletics over many years are a cause for deep dismay and yet another indication of how much we as a sport still have to do to ensure that athletics is free of doping and seen to be fair and clean," he said.
"I have on many occasions expressed our policy of zero tolerance for doping and our commitment to doing everything we as one of the six IAAF Area associations can to enforce the existing rules.
"But we are under no illusions that there is an easy fix, and we are currently developing other ideas that we can introduce in Europe as examples for the rest of the sport around the world or propose to the IAAF and WADA for worldwide implementation."
August 2015: Exclusive: Calls for greater targeted testing following data showing hundreds of abnormal blood samples
July 2015: Mo Farah cleared of any wrongdoing by UK Athletics over links with coach Salazar
June 2015: Alan Hubbard: Do the public even care if athletes have taken drugs or not?
June 2015: Mo Farah's coach Alberto Salazar and training partner Rupp accused of doping
January 2015: Lawsuits to be filed against German TV station after "systematic doping" in Russian athletics accusation