Russia's athletes should stay banned from international competition and not be allowed to take part in the Rio Games, says a leading Olympic official.

Scandal-hit Russia will likely discover Friday that it has not done enough to get back into world track and field's governing body, the IAAF, in time for its athletes to compete at the Rio Olympics.

World record holder Etiene Medeiros, one of Olympic hosts' Brazil's top hopes of a medal at the Rio Games, has tested positive for a banned substance.

Despite financial and organisational problems that have delayed other construction projects for the Rio de Janeiro Olympics, the largest athletes' village in the long history of the Games is unveiled in the city on Wednesday.

Scientists find dangerous drug-resistant "super bacteria" off beaches in Rio de Janeiro that will host Olympic swimming events and in a lagoon where rowing and canoe athletes will compete when the Games start on August 5.

Fiery Australian tennis star Nick Kyrgios pulls out of the Rio Olympics, blaming "unwarranted attacks" on him by Australian Olympic chiefs after he was warned to behave.

Nick Kyrgios has pulled out of Rio 2016, accusing the Australian Olympic Committee (AOC) of "unfair and unjust treatment" and "unwarranted attacks".

Professional boxers can compete at the upcoming Olympic Games in Rio de Janeiro, the sport's governing body ruled in a landmark decision on Wednesday.

The World Health Organization (WHO) plays down concerns over the spread of the Zika virus, amid calls for the Rio Olympics to be postponed.

A senior International Olympic Committee (IOC) official says he takes allegations of illegal payments to help Tokyo secure the 2020 Games "seriously" but said his group will not conduct a probe of their own.

Brazilian investigators expand their probe into possible corruption around the staging of the Olympic Games in Rio de Janeiro this August to include all the venues and services financed with federal funds, a lead prosecutor told Reuters.

As Rio de Janeiro prepares to play Olympic host, one art exhibit is flying a less than celebratory five-ring flag portraying five youngsters shot dead by police in this often deadly city.

Twice Olympic shooting champion Michael Diamond has been arrested for drunk driving and charged with firearms offences, the Australian Olympic Committee says on Monday.

Russia's sports ministry says on Wednesday it fully supports actions by the International Olympic Committee (IOC) to bar athletes who dope from competitions, but said clean athletes should not be excluded from the Rio games.

Australia captain Steven Smith and his team have been warned about risks associated with the Zika virus ahead of their tour of the West Indies next month.

Neymar says sitting out of the Copa America is worth it for the chance to lead Brazil to gold in front of a home crowd at the Rio Olympics in August.

Australia's Olympians will be issued with free super-strength condoms in Rio to minimise any infection from the Zika virus, officials say on Monday.

The International Olympic Committee yesterday granted a 'wild card' for shooter Abdullah Hel Baki for the upcoming Olympic Games to be held in Rio de Janeiro, Brazil from August 5 to 21.

Argentina captain Lionel Messi admits he would have liked play at the Olympic Games after he was left out of the squad in order to take part in the Copa America Centenario.