NEW YORK (AFP) - Billy Paul, a star from the Philadelphia soul scene who won fame with Me And Mrs Jones before drawing controversy with his racially charged politics, died on Sunday. He was 80.

Known for his uplifting, mellifluous voice, he won a Grammy Award and helped shape the course of modern R&B but fell on the losing end of one of the music industry's legendary tales of poor marketing.

"We regret to announce with a heavy heart that Billy has passed away today at home after a serious medical condition," a statement on his website said.

Born as Paul Williams in Philadelphia, he came of age as the eastern city became an epicentre of a style of soul music known for smooth and jazzy melodies.

He performed in his youth alongside legends such as Charlie Parker and Nina Simone.

Paul topped the mainstream charts in 1972 with Me And Mrs Jones, a light-touch song about an extra-marital affair that has been covered by a range of artists including pop duo Hall & Oates and crooner Michael Buble.

But in a decision that would prove commercially disastrous, he followed up the hit not with another smooth soul song but Am I Black Enough For You?, a funky number with allusions to the Black Power movement.

Paul said he opposed the timing of the release of the more provocative song. Legendary music executive Clive Davis said he had also pushed against the move on commercial grounds, although he praised Am I Black Enough For You? on artistic merit.

"For a long time I was angry about it," he told Blues and Soul magazine after the release of a 2009 documentary about the song in Sweden, where he had a particularly strong following.

"The song is ahead of its time," he said.

But in an interview with the review site Little White Lies, Paul said decades later he received the most requests for the song among white audiences.

"So it makes me very comfortable, and now it's very, very popular. It caught up with time - we got a black president now," he said, referring to Mr Barack Obama.

Artist and producer Questlove, best known as the percussionist of The Roots, said in a Swedish documentary that Paul should be considered the forerunner of soul icons Stevie Wonder and Marvin Gaye.

"Billy Paul, in every aspect of his presentation, was the first person to bring reality" into the music, Questlove said.