LAUSANNE, Switzerland (AP) — The Court of Arbitration of Sport will begin appeals hearings on Monday for 39 Russian athletes disqualified from the 2014 Sochi Winter Games for doping and banned for life from the Olympics.

Two key witnesses, Russian whistleblower Grigory Rodchenkov and World Anti-Doping Agency investigator Richard McLaren, will testify by video or telephone link to the closed-door hearings, CAS said in a statement Wednesday.

The court said the combined hearings should last for six days at a conference center in Geneva, near the European headquarters of the United Nations.

One panel of three judges will hear 28 cases and a second trio will judge 11. Two of the judges — Christoph Vedder and Dirk-Reiner Martens, both from Germany — will sit on both three-man panels, CAS said.

Verdicts are expected by Friday, Feb. 2, one week before the Pyeongchang Olympics opening ceremony in South Korea.

A further three appeal cases in biathlon will not be heard next week, the court said.

All 42 athletes deny being part of a state-backed doping program for the Sochi Olympics.

The first group of athletes whose hearings have been combined are in bobsled, cross-country skiing, skeleton and speed skating. They include athletes who have continued to compete in World Cup races not controlled by the IOC.

The second group of 11 cases is from bobsled, luge and women's ice hockey.