Tennis legend Martina Navratilova hit out at the IOC on Tuesday, accusing the Olympic body of "putting their head in the sand" over gay rights.
The openly gay former tennis star, speaking at the United Nations in New York, also took a swipe at Qatar, hosts of the football World Cup in 2022.
But she was most animated about what she sees as the International Olympic Committee's (IOC) inaction ahead of the Sochi Winter Olympics in February in Russia, a country which has courted criticism for legislation that gay activists and critics say discriminates against homosexuals.
"In Qatar for example, where the World Cup is going to be, homosexual activity is punishable by jail terms," said Navratilova, who was born in what was then Czechoslovakia but became a US citizen.
"My disappointment is with the IOC for really putting their head in the sand and not wanting to make any waves... I think the IOC needs to stand up better for their athletes, quite frankly."
"I have never supported boycott (of Sochi) because the athletes would be the only ones that will suffer from a boycott," she told a press conference, adding: "Nobody gains by that."
Navratilova, who won 18 Grand slams in a glittering career, said that the US also had progress to make on gay rights.
"We need to clean up our own country first," said the 57-year-old, who was to participate in a UN debate on homophobia in sport on Human Rights Day on Tuesday.
Jason Collins, a journeyman NBA player who revealed his homosexuality earlier this year, said he also wanted Olympic chiefs to take action.
"I don't know how much the IOC can do in pushing the Russian government to end their gay propaganda laws, but they can definitely do more," he said.
"People should be able to live their lives openly, should be encouraged to be themselves.
"The IOC and FIFA (football's world governing body) should look when they are selecting a city or country to host at whom they choose to associate their brand with, is it a government that would openly oppress their own people?"