The National Basketball Association (NBA) is investigating an audio recording posted online which allegedy reveals the owner of the Los Angeles Clippers telling his girlfriend not to post photographs of herself with African-Americans or bring them to games involving the basketball team.
Celebrity news site TMZ.com published the 10-minute recording on its website late on Friday, describing it as a taped conversation between billionaire Donald Sterling and a model who goes by the name V Stiviano, according to the Reuters news agency.
Sterling later told TMZ the recording "does not reflect his views".
"The audio recording posted by TMZ is truly offensive and disturbing, and we intend to get to the bottom of it as quickly as possible," Adam Silver, the NBA commissioner, said at a news conference on Saturday night.
The recording has been sharply criticised by civil rights leaders, fans and players.
Barack Obama, the US president who is currently visiting Asia, said on Sunday that the comments were "incredibly offensive [and] racist".
"When ignorant folks want to advertise their ignorance you don't really have to do anything, you just let them talk," Obama told reporters at a news conference in Malaysia.
Legacy of racism
Obama said the recording was an example of the US continuing to wrestle with the legacy of racism, slavery and segregation, and urged Americans to be "steady and clear in denouncing" discrimination.
Clippers all-star player Chris Paul called the tape "a very serious issue," and the Miami Heat's LeBron James was quoted as saying there was "no room for Donald Sterling in our league".
It was not immediately clear when and how the conversation was recorded.
Silver said the league would move swiftly to determine the authenticity of the recording and its context. Sterling has agreed not to attend his team's playoff game on Sunday against the Golden State Warriors, Silver said.
|NBA commissioner Adam Silver said the recording was "truly offensive and disturbing" [AFP]
The commissioner said a range of sanctions was possible but declined to predict the outcome of the investigation, saying Sterling should be given a chance to present his side.
Andy Roeser, the president of Clippers, issued a statement on Saturday saying they have listened to the tape on TMZ.
"We do not know if it is legitimate or it has been altered. We do know that the woman on the tape - who we believe released it to TMZ - is the defendant in a lawsuit brought by the Sterling family," the statement said.
"Mr Sterling is emphatic that what is reflected on that recording is not consistent with, nor does it reflect his views, beliefs or feelings."
'Racist in your heart'
The tape appears to be an argument over photos Stiviano posted to the social networking website Instagram.
"People call you and tell you that I have black people on my Instagram. And it bothers you," Stiviano says, according to a version of the tape at TMZ.com. In the tape, Stiviano says she herself is of Latino and black heritage.
"Yeah, it bothers me a lot that you want to promo ... broadcast that you're associating with black people. Do you have to?" Sterling says on the tape, according to TMZ.
At another point, Stiviano says Sterling does not want her to bring black people to basketball games, and tells him: "I'm sorry that you're still racist in your heart."