Mutko also insisted the number of athletes from Russia who will have tested positive for banned substances by the end of 2015 “will be the same as three or five years ago” and will not be “at the same level as in the United States, France or Italy”.

The outspoken Sports Minister, who has constantly defended Russian sport and dismissed suggestions of state-supported doping in the nation, launched a scathing attack on the doping testing system in the U.S, claiming American athletes are only tested once every four years before Olympic Games.

“We are not the United States, or the NBA, or the NHL,” Mutko told reporters.

“We all are open both in volleyball and in basketball.

“We are a different country.

“Nobody does doping tests at those (U.S) leagues and boxing associations.

"They do doping tests once every four years, when coming to the Olympics.

“Everybody should be checked up before the trips.

“Certainly, we wish the system of doping control would be equidistant.”

Mutko’s comments come after he warned the number of Russians to have failed tests for meldonium, the heart-attack drug added to the World Anti-Doping Agency (WADA) prohibited list on January 1, could reach 30 in the near future.

He had previously suggested 27 out of the 123 confirmed cases by WADA involved athletes from the global sporting superpower.

The substance, developed in Latvia, was added to WADA’s banned list due to “evidence of its use by athletes with the intention of enhancing performance”.

It hit the headlines when five-time tennis Grand Slam champion Maria Sharapova admitted she had tested positive at the Australian Open in January earlier this month.

Track cyclists Anastasia Chulkova and Pavel Yakushevsky reportedly became the latest Russian athletes to test positive for the substance yesterday.

Chulkova boasts a gold medal from the 2012 International Cycling Union Track Cycling World Championships in Melbourne, where she won the women’s points race.

Her 28-year-old team-mate Yakushevsky claimed a team sprint bronze medal at the 2013 European Track Cycling Championships in Apeldoorn.

A number of high-ranking Russian sportspeople have been implicated, including four-time world champion swimmer Yuliya Efimova, who won the 100 metres breaststroke title at last year's home World Championships in Kazan and is considered the country's leading swimmer.

Mutko, however, feels a lot of the cases concerning Russian athletes were not deliberate and has again accused WADA of a lack of research into the effects of the drug on athletes.

“An athlete should be punished fairly but now it turns out that they were taking meldonium unintentionally,” Mutko said.

"WADA has not carried out any research on how long the substance stays in the human body.

“We filed a request and were answered that there had been no research."

Russia has been embroiled in a new scandal surrounding Russian swimming after British newspaper The Times alleged the presence of a systematic doping programme in the nation.

The revelations, which are being investigated by WADA and the International Swimming Federation, came after the WADA Independent Commission reports uncovered state-supported doping within Russian athletics.

The reports led to the suspension of the All-Russia Athletic Federation by the International Association of Athletics Federations and, if a decision due in May does not go their way, Russian athletes could miss out on competing at the Olympic Games in Rio de Janeiro.