Though Mr Tammjärv and Mr Veerpalu weren't available for comment, the Estonian Ski Association wrote in a press release on Friday morning that the two athletes confirmed to their coach, Anti Saarepuu, that the suspicions are justified.

Tammjärv, Veerpalu admitted use of doping, association says

"The Estonian Ski Association regrettably has to admit that Estonian skiers Tammjärv and Veerpalu have confirmed to their coach Anti Saarepuu that they have been doping," the association wrote. "There is no justification whatsoever for doping," the statement continued.

The association rejects any notion of its own involvement, pointing out in its press release that the athletes in question have been active and trained "independently from the Estonian Ski Association for years" as part of Team Haanja.

"Taking into account the fact that the use of doping is forbidden also according to the contracts between skiers and the Estonian Ski Association, and the Ski Association has publicly condemned the use of doping, we consider the harsh punishment of the athletes in question to be appropriate," the association added.

Ski Association to look into Alaver, Veerpalu connections

The management of the Ski Association will meet as soon as at all possible to discuss its next steps, and how to determine the extent and the way Estonian athletes and individuals connected to them have been part of the internationally operating organised crime ring the Austrian police operation had targeted.

President of the Estonian Ski Association, Andreas Laane, said that the bigger picture needs to be taken into account, as Kazakh skier Alexey Poltoranin has admitted his involvement as well. "[Karel Tammjärv and Andreas Veerpalu's] Team Haanja as well as Poltoranin's own team are connected with Estonian skiing coaches Mati Alaver and Andrus Veerpalu. Both men have been Alexey Poltoranin's coaches for a long time," the press release stated.

Coach previously involved in doping scandal in 2011

One of the arrested athletes, Andreas Veerpalu is the son of former Estonian cross-country skiier Andrus Veerpalu, who himself was at the centre of a doping scandal in 2011, shortly after retiring from the sport.

Veerpalu senior, however, was acquitted of the charges in 2013 by the Court of Arbitration for Sport (CAS), an international quasi-judicial body established to settle disputes related to sport through arbitration, headquartered in Lausanne, Switzerland.

Mr Veerpalu at the time was acquitted on a technicality, the court stating in its ruling that "there are many factors in this case which tend to indicate that the Athlete did in fact himself" apply exogenous human growth hormone doping. But the court eventually ruled that the decision limit, the cut-off time for a test result to be considered an adverse analytical finding, in this case was not enough to uphold Mr Veerpalu's doping conviction.