Rainbow George, political dreamer and Hampstead’s self-styled “village idiot”, is not known for being especially publicity-shy.

His appearances in this diary alone are legion, while his home is filled with countless press cuttings about his wacky deeds or latest political party.

Yet despite his history of close contact with journalists, the 74-year-old – real name George Weiss – has apparently been sitting on a news bombshell of epic proportions these past 40 years.

According to a Daily Mirror front page exclusive on Friday, Mr Weiss – who now lives in Highgate – has finally broken his silence on why his “friend” Lord Lucan was driven to kill in 1974.

He said the aristocrat murdered his nanny after a kitten he had sent to his children and estranged wife was posted back through his door with its throat cut.

Mr Weiss told the paper: “He saw no way back into family life and the life of his children. It tipped him over the edge and it made him decide to uncreate his wife.”

Mr Weiss said he heard about the cat while playing backgammon with Lucan the day before Sandra Rivett was bludgeoned to death and his wife Veronica attacked.

He added: “I believe he was plotting his wife’s murder. He was in a world of his own.”