Russian athletes will file a class action suit against the ban preventing their participation in the Rio Olympic Games, as Russia's sports minister said a decision to prevent its weightlifters from competing was "psychotic".

The class action suit will be filed to the Court of Arbitration for Sport next week, the head of the Russian Athletics Federation Mikhail Butov has said.

The International Association of Athletics Federations (IAAF) last week upheld the ban, insisting that a "deep-seated culture of doping" remained in Russia.

The Russian track and field team will currently not be allowed to compete at the Games, though the International Olympic Committee (IOC) has said Russians could take part under the country's flag if cleared by the IAAF or the Arbitration Court.

IOC president Thomas Bach said the Russians would need to be individually evaluated, adding that the state of Russia's anti-doping authority put "very serious doubts on the presumption of innocence".

Russian officials labelled the ban "legally indefensible" and "unfair" on athletes who have never taken part in doping. 

In a further blow to the country's Olympic hopes, Russia's weightlifters now face exclusion from Rio after being handed a year-long suspension over failed retests on samples from the 2008 and 2012 Games.

Vitaly Mutko, Russia's sports minister, said the ruling from the International Weightlifting Federation (IWF) was like a "psychotic episode". 

Mutko condemned the decision as "a departure from ... principals and norms", asking: "How can you punish a team which should go to the Olympic Games in 2016 for violations from 2008 or 2012?"

Weightlifters from Kazakhstan and Belarus have also been suspended by the IWF, which says its "zero tolerance" approach to doping is necessary to "protect clean athletes".

The Rio Olympic Games starts in six weeks' time, but preparations have been overshadowed by doping revelations and concerns about the Zika virus.

Rory McIlroy has pulled out of the event, after health experts called for the Games to be cancelled or postponed due to the virus - a move rejected by the IOC and World Health Organisation.

(Sky News)