SOUR NOTE: Friends of Paul McCartney say Heather Mills tried to put the squeeze on her husband, who reportedly wants custody of daughter Beatrice.

October 20, 2006 — Paul McCartney's one-legged, topless-model wife reportedly tried to blackmail the beloved Beatle by telling him that he better give her as much as half of his $1.5 billion fortune - or else she'd drag him through the mud.

Heather Mills McCartney, 38, threatened to ruin her estranged hubby's sterling reputation sometime in August, a McCartney pal told The Sun of London.

Sir Paul balked at her alleged shakedown effort - after which secret court papers containing outrageous claims of violence, beatings, a stabbing and endless mental cruelty somehow leaked to the media this week.

"She is a lying, scheming, blackmailing little bitch," said one of the singer's friends, who is convinced her camp was behind the leak