US civil rights leader the Rev Jesse Jackson has apologised for "regretfully crude" remarks he made about Democratic presidential nominee Barack Obama.
In a reference to Mr Obama, Mr Jackson had said on US Fox News: "I want to cut his nuts off", not knowing his comments were picked up by a live microphone.
Mr Jackson had said he thought Mr Obama was "speaking down to black people".
The reverend said he was "very sorry for any harm" and that he had "deep and wide" support for the Obama campaign.
Mr Jackson has been a key civil rights campaigner and was unsuccessful when running for the Democratic presidential nomination in 1984.
Mr Jackson was talking to a guest ahead of a live interview on Fox on Sunday in Chicago when he made the remarks.
He was discussing the question of Mr Obama's speeches on morality that the presidential candidate had made in black churches.
He of course accepts Reverend Jackson's apology
Bill Burton, Obama campaign
He said he thought there were other key issues facing the black community, such as unemployment and crime.
The reverend added: "See, Barack been, um, talking down to black people on this faith based... I want to cut his nuts off... Barack... he's talking down to black people."
Mr Jackson said he had called the Obama campaign to apologise "for any harm or hurt that this hot mic private conversation may have caused".
"My support for Senator Obama's campaign is wide, deep and unequivocal."
Mr Jackson said he was trying to appeal to Mr Obama for "the moral content of his message to not only deal with the personal and moral responsibility of black males, but to deal with the collective moral responsibility of government and the public policy".
A spokesman for the Obama campaign, Bill Burton, said the presidential candidate would "continue to speak out about our responsibilities to ourselves and each other, and he of course accepts Reverend Jackson's apology".
Mr Obama has had a number of problems with clergymen during his election campaign.
In May he said he was "deeply disappointed" with a sermon by supporter Father Michael Pfleger, who suggested presidential rival Hillary Clinton had felt "entitled" to beat Mr Obama because she was white.
Earlier, Mr Obama denounced the claim by Rev Jeremiah Wright, who officiated at his wedding and baptised his daughters, that the 9/11 attacks were an example of "America's chickens coming home to roost".
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