The athletes and ROC had challenged a ban by the International Association of Athletics Federations in June that will keep the team from going to the Summer Olympics.
The CAS decision comes amid calls from athletes and anti-doping officials for the IOC to ban Russia from the Rio Olympics following the release of another WADA report this week that revealed even more widespread doping issues than previously known.
On Monday, Canadian lawyer Richard McLaren released a report that confirmed allegations of doping and tampering with samples during the Sochi Olympics and revealed a larger system of covering up positive tests of doped Russian athletes that reached the highest levels of sport.
Termed the Disappearing Positive Methodology, the system revealed in the report included the Ministry of Sport, Center of Sports Preparation of the National Teams of Russia (CSP), Federal Security Service (FSB) and the Moscow and Sochi labs working in coordination from 2011 to 2015 to cover up 643 positive tests of athletes across 29 Olympic sports.
The system was led by Yury Nagognykh, the deputy sports minister and a member of the Russian Olympic Committee’s executive board, and included several top Russian sports officials.
The McLaren report confirmed allegations that Dr. Grigory Rodchenkov, former director of the Moscow lab, made about the FSB helping cover up doping at the Sochi Games by unsealing bottles previously thought to be tamperproof to allow Rodchenkov to swap out dirty urine for clean urine.
Following the report, president Thomas Bach said the IOC “will not hesitate to take the toughest sanctions available” against individuals or organizations implicated in the McLaren report. The IOC said it is exploring legal options for a ban of Russia entirely from the upcoming Olympics but wanted to consider the CAS decision.
On Wednesday, anti-doping leaders from 14 countries called upon Bach and the IOC to ban Russia immediately. The letter was signed by U.S. Anti-Doping Agency CEO Travis Tygart as well as the heads of nine European national anti-doping organizations.
Following the release of the McLaren report, WADA and the Institute of National Anti-Doping Organizations (iNADO) also called for a ban of Russia.
The CAS decision likely gives the IOC framework for how it could proceed. Whatever decision it would make must come quickly, as the Games open on Aug. 5.