Bruce Williams, Dr. Dre's former longtime confidante, claims Sharpton made the threat because he was offended by certain rap lyrics and unhappy about a feud between rappers 50 Cent and The Game, the New York Post reported.

"He said if we didn't have ($500,000), we marching. It's that easy," Williams told hiphopdx.com.

But Sharpton told the Post he never spoke to Dr. Dre and doesn't remember meeting Williams.

Although Sharpton dismissed Williams' claims as "absurd," Williams insisted he and the social activist helped set up the 2005 public reconciliation between 50 Cent and The Game.

"When that beef between 50 Cent and The Game went public, Al Sharpton called over and asked for half-a-million dollars," Williams said in his book "Rollin' With Dre: The Unauthorized Account."

"Otherwise he was going to bring the heat. We gave him $250,000. Then we had The Game and 50 make up in public," Williams wrote.

The rappers announced a joint gift of $253,000 to the Boys Choir of Harlem at a news conference, the Post said.