Russia's anti-doping agency and athletics body "were rotten to the core", International Olympic Committee vice-president John Coates said Friday, hours before a decision on whether their track and field team can compete in Rio.

Coates slammed a "massive injustice" as he belatedly awarded a London 2012 Olympics gold medal to Australia's Jared Tallent, who was promoted from silver after a Russian doping case.

Tallent came second in the 2012 Games' 50km walk only for the winner, Russia's Sergey Kirdyapkin, to be stripped of his title this year after he was found guilty of doping.

Coates, who is also president of the Australian Olympic Committee, said he was honoured to finally present Tallent with his winner's medal, ahead of what will now be his title defence in Rio de Janeiro in August.

"Presenting an Olympic medal is always an honour," Coates said in Melbourne.

"But more so on this occasion to be part of rectifying, in some way, the massive injustice perpetrated on Jared by a doping cheat and aided by a Russian Anti-Doping Agency and Russian Athletics Federation that were rotten to the core."

The Court of Arbitration for Sport (CAS) ruled in March to strip six Russian track and field stars -- including Kirdyapkin -- of their titles and medals from a period ranging from 2009 to 2013. 

The decision came after CAS upheld an appeal by world athletics body the IAAF, which had criticised Russia's "selective" disqualification of these athletes' results, accusing the country of annulling them only for minor competitions. 

The awarding of Tallent's gold medal came on the same day that the IAAF meets in Vienna to decide whether to bar the Russian Athletics Federation from the Rio Games.

The Russian organisation was suspended in November over explosive doping and corruption allegations.

Russia's problems were compounded by a bombshell report by the World Anti-Doping Agency on Wednesday, which claimed hundreds of attempts to carry out drug tests on Russian athletes this year have been thwarted.

Coates praised Tallent as fine example of a "clean" athlete.

"An athlete who will now be proudly, and rightly, representing Australia in Rio as the current Olympic champion and Olympic record-holder," he said at a ceremony where the national anthem was sung and the Australian flag raised.

"Jared, you are a great Australian and it is my honour to present you with your gold medal."

Source: AFP