LAUSANNE (AFP) - A decision over whether to overturn Russia's four-year ban from international sport due to state-sanctioned doping will be known "by the end of this year", the Court of Arbitration for Sport (CAS) said on Thursday (Nov 5).

A four-day arbitration hearing between the World Anti-Doping Agency (Wada) and the Russian Anti-Doping Agency (Rusada) wrapped up after four days of talks at a secret location.

The showdown took place following Wada's decision last year to declare Rusada non-compliant after being accused of manipulating drug-testing data.

The ensuing ban meant Russia would miss the re-arranged Tokyo Olympics next year as well as football's 2022 World Cup in Qatar and the 2022 Winter Olympics in China.

"In light of the travel restrictions and sanitary measures in place due to the Covid-19 pandemic, the hearing took place in a mixed format with the majority of participants joining via video link," said CAS in a statement.

"The Arbitral Panel in charge of the arbitration will now deliberate and prepare the Arbitral Award containing its decision.

"While it is difficult to predict exactly how long this process will take, it is anticipated that the Arbitral Award will be notified to the parties by the end of this year."

Russia considers its ban to be legally indefensible while former prime minister Dmitry Medvedev described the suspension as "chronic anti-Russian hysteria".

"Wada is satisfied with how we presented our case and we now look forward to receiving the decision of the Panel," said Wada president Witold Banka on Thursday.

"As at every other stage, we are following due process in relation to Rusada's compliance procedure as we continue to deal effectively with this complex matter."

Landmark week

The hearing was billed as a landmark week for Russian sport and global anti-doping efforts.

Wada, formed in 1999, also has plenty on the line after the US threatened to pull its annual US$2.7 million (S$3.64 million) financing.

US lawmakers accused Wada of failing to implement governance reforms and have criticised the handling of the Russian scandal.

Also, the International Olympic Committee and sports federations are expecting clear directives from CAS, eight months before the Tokyo Olympics.

The Russian saga is now uncomfortably into its fifth year.

In May 2016, Grigory Rodchenkov, the former head of Moscow's anti-doping laboratory, blew the whistle over state-backed doping at the 2014 Sochi Olympics.

Barely two weeks before the 2016 Olympics in July that year, Wada called for Russia to be banned from the Rio Games.

The IOC, however, stopped short of an outright ban and said individual federations would decide whether to allow Russian athletes to compete.

In 2017, the IOC banned the Russian Olympic Committee from the 2018 Pyeongchang Winter Games, but allowed clean Russian athletes to take part as neutral competitors.

A total of 168 Russians eventually competed.

Then, in September 2018, Wada controversially lifted its ban on Rusada, despite not having been granted access to its doping-tainted Moscow laboratory.

Russia finally handed over lab data to Wada in January 2019.

However, in yet another twist, in September Wada gave Russia three weeks to explain "inconsistencies" in the data.

World Athletics announced it had suspended the process of reinstating Russia's athletics federation and was contemplating expelling the country entirely from the sport due to the doping scandal.

Wada then decided to ban Russia for four years over the manipulated data.