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.

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

Sprint king Usain Bolt aims to crown his legacy with an unprecedented Olympic threepeat at the Rio Games, and to

Russia on Tuesday pledged to cooperate with anti-doping and international athletics authorities after a damning report into allegations of doping and corruption in athletics in the country.

Jamaica's Shelly-Ann Fraser-Pryce roared to an unprecedented third women's 100 metres world title in a flash of green dreadlocks on Monday.

Forbes magazine has made a list of the highest paid celebrities in the world. While movie starts and singers are littered throughout the list, athletes also make up a large portion of the list, including the top two spots.

Gay, who last summer completed a one-year ban for a 2013 positive doping test and had been mentored by Lance Brauman for years, began working with Smith's sprint group this week.

Usain Bolt ended his injury-plagued season early, having competed in just three races in 2014.