Ustyugov is set to lose the Olympic gold medal he won as part of the 4x7.5 kilometres relay team at the 2014 Winter Olympic Games in Sochi after he was sanctioned by the International Biathlon Union's (IBU) Anti-Doping Hearing Panel based on analysis of the Moscow Laboratory data.

The retired 35-year-old was also banned for two years but has challenged the decision at the CAS, which is set to hear his appeal on October 20.

The IBU said Ustyugov had "committed an Article 2.2 ADRV [anti-doping rule violation] under the 2012 IBU Anti-Doping Rules" by using the prohibited substance oxandrolone.

Ustyugov told Russia's official state news agency TASS that he had spent "hundreds of thousands" on legal fees challenging the IBU ruling, and claimed the Russian athletes found guilty of doping offences following analysis of the Moscow Laboratory data had been pre-judged.

"If it weren't for friends, you could have died of despair," Ustyugov said. 

"I conducted many examinations, collected evidence, plus it is necessary to pay for the work of lawyers. 

"This has already cost hundreds of thousands of dollars. 

"Without influential friends, an ordinary athlete from Russia simply cannot fight with the soulless system of world sports, in our sport no one has such material resources.

"And the presumption of innocence was stripped of us long ago. 

"The World Anti-Doping Agency (WADA) and the International Olympic Committee (IOC) have created a system in which, if they make a mistake, it is almost impossible to defend themselves."

Ustyugov announced in March that he would be appealing the decision to CAS.

TASS reported Ustyugov has undergone genetic tests to prove his innocence.

Ustyugov has also reportedly filed a lawsuit against the IBU in the Austrian state court after he was charged in a separate case by the Biathlon Integrity Unit (BIU).

The BIU charged Ustyugov because of abnormalities in his Athlete Biological Passport in the period between January 2010 and February 2014.

Ustyugov is a double Olympic gold medallist, having won the mass start at Vancouver 2010 and also picked up a bronze in the relay at those Games.

"Emotions have not subsided, but on the contrary, they flare up. 

"Anger, despair - all the feelings that I experience from day to day are difficult to convey.

"I have never felt so helpless, a little person who fell under the pressure of punishers from WADA and the IOC."