Five athletes from Austria, Kazakhstan and Estonia were arrested on Wednesday in anti-doping raids at the event in the Austrian resort of Seefeld, police said.
The raids were part of a broader operation targeting a Germany-based "criminal organisation" suspected of having carried out blood doping for years, the Austrian police said.
A 40-year-old sports doctor is believed to be at the centre of the organisation, the police said in a statement, adding that he was also arrested in Germany on Wednesday.
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Austrian media quoted an official from the country's skiing federation as saying the two Austrians arrested were cross-country skiers Hauke and Dominik Baldauf, both 26.
Max Hauke und Dominik Baldauf
Image credit: Imago
"Athletes have been caught using unauthorised methods or substances. Unfortunately, it shocks me, two of our athletes are among them. They have been taken into custody, Baldauf and Hauke," the federation's sporting director for cross-country skiing and biathlon, Markus Gandler, told the APA news agency.
A video leaked by a policeman and released by Norwegian media outlet NRK allegedly shows Hauke in the middle of a transfusion as police storm his room.
Austrian outlet DerStandard reported that the officer who recorded and leaked the video has been removed from his job and is facing disciplinary proceedings.
NRK showed the video to British skier Andrew Young, who has regularly trained with Hauke throughout his career.
Young told the outlet: "I am getting nauseous. It is disgusting to look at.
"It's not nice. It is difficult. There is no room for it in sports and I do not realize that he was doing it."
Young isn't the only British skier to voice criticism of those arrested. Callum Smith also expressed his bewilderment at what had happened.
In total nine people were arrested in 16 raids in Seefeld and Germany, the Austrian police said, adding the operation was co-ordinated with the German authorities. One of the athletes was caught in the act of doping, officials said.
Munich's state prosecutor's office said the investigation was triggered by statements made by Austrian cross-country skier and doping offender Johannes Duerr to a German broadcaster earlier this year.
Duerr, who was caught doping during the 2014 Winter Olympics in Sochi, Russia, had talked to German broadcaster ARD in January.
The World Anti-Doping Agency (WADA) said it had provided information to the investigation.
"The raids were part of a wider police operation targeting criminals from a number of European countries, and WADA's Intelligence and Investigations Department has been providing information and other assistance to the authorities in the course of their operation," WADA said in a statement.
Two other people were arrested in Seefeld while another two, including the sports doctor, were arrested in Germany, the police said.
The raids were part of an investigation that has lasted several months on suspicion of "professional sport fraud" and "use of prohibited substances and methods for doping purposes".
This is not the first time that Austrian skiing has been hit by a doping case.
At the 2006 Olympics in Turin, the Austrian cross country and biathlon teams had their headquarters raided by Italian police and drugs testers in a high-profile doping scandal.
None tested positive but half a dozen athletes were banned for life after the discovery of syringes and other equipment, and the Austrian Olympic Committee was fined for anti-doping rules violations by the International Olympic Committee.
Additional reporting via Reuters
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