LAUSANNE • The World Anti-Doping Agency (Wada) will take its case for the exclusion of Russia from international sporting competitions to the Court of Arbitration for Sport (CAS) "by the weekend", an official told Agence France-Presse on Wednesday night.

The world's highest sporting court will then have to decide whether to confirm the four-year ban imposed on Russia last month, or listen to the country's case against the sanction.

Under the suspension, Russian athletes will still be allowed to compete in the Tokyo Olympics this year, but only if they demonstrate that they were not part of the state-sponsored doping network.

Russia's athletics body, Rusaf, has come under pressure from athletes for its handling of the scandal, which was deepened after Wada deemed that data from an anti-doping laboratory in Moscow had been manipulated.

On Tuesday, three-time high-jump world champion Mariya Lasitskene urged her fellow competitors to "change Russian athletics' current situation".

A vocal critic of the Russian sporting authorities, she has already warned she would quit Russia and train elsewhere so as not to miss the Tokyo Games after being excluded from Rio 2016 due to a similar ban in 2015.

Esteemed Olympic historian Bill Mallon, however, feels the 26-year-old will not be excluded again, saying: "She's been critical of the Russian doping system so I think she'll be allowed to compete and if she is, she'll definitely win gold."

But the International Olympic Committee (IOC) will not discuss the possibility of Russian athletes participating in Tokyo - as well as the size of their contingent, overall appearance and uniforms - until the final CAS ruling is made.

After an IOC executive board meeting on Wednesday, a spokesman said: "We will wait for a decision by CAS before doing that."

No date has yet been set for a CAS ruling.

AGENCE FRANCE-PRESSE, REUTERS