Hollywood- HOLLYWOOD oil heir Brandon Davis just poured gasoline on the Paris Hilton N-word furor, claiming that Hilton regularly uses the racial slur as well as slurs against other minorities.

Davis, an old friend of Hilton who had a falling out with her this year, came forward after it was reported that Hilton used the N-word in a scene caught on videotape. Hilton later issued a statement saying, “Anyone who knows me knows that this is not me. I love everybody and am not a person who discriminates against anyone – ever.”

But Davis tells this week’s National Enquirer: “Not true. She was forever using the ‘N-word.’ I told her not to use it. It was offensive. But she just laughed. She is a racist, plus an idiot. Every black person she referred to was a ‘n- – – – -.’ ”

Davis, the grandson of recently deceased oil billionaire and movie mogul Marvin Davis and boyfriend of “O.C.” starlet Mischa Barton, continued, “She uses the word all the time, and I’ve known her all of her life. It’s ‘n- – – – – this’ and ‘n- – – – – that.’ She’s a disgrace. She is a racist!

“She puts down Jews and other minorities, too. And I’m Jewish. I found it depressing . . . I finally had enough of her attitude six months ago, and I finished with her. I don’t want anything to do with her. I don’t need anything from her. She is no longer my friend. She’s just not a nice person.”

Davis said that he never heard Hilton use racist language around her best friend and “Simple Life” co-star Nicole Richie, who is black. “I know Nicole,” Davis said. “She is a very good person.”

Hilton’s publicist said the hotel heiress was on a plane yesterday and could not be reached. We also left a detailed message for Richie’s rep to see if Nicole wanted to defend her friend against Davis’ charges, but we didn’t hear back.

Meanwhile, “diversity promoter” Asa Khalif, president of the Philadelphia-based Racial Unity USA, says his group is considering boycotting all things Paris Hilton.

“Once we receive a copy of the tape, we will move from there,” Khalif said in a press release yesterday.

“Racial Unity USA has not ruled out protests and boycotts once Hilton’s alleged comments are confirmed on tape. Racial Unity USA will stand up against anyone who promotes hate and divisiveness, even if that anyone is Paris Hilton.”