George Best's son Calum has revealed that the Manchester United legend once tried to kiss him while he was in a drunken state.

The Irish footballer battled with alcoholism during his life, which resulted in a liver transplant in 2001, but the retired sportsman died four years later at the age of 59.

In a book that's being serialised by the Daily Mail, Calum recalled one disturbing incident when he fell asleep in his father's bed and the footballer drunkenly tried to kiss his son after mistaking him for a woman.

"I am about to start trying to go back to sleep when Dad rolls over, puts his face in front of mine and kisses me, as in, he puts his tongue in my mouth - that kind of kiss," writes Calum.

"I freeze. 'What's going on?' I'm old enough to know what a French kiss is, but why is Dad doing it to me?"

In 1968, Best was named the European Footballer of the Year and the FWA Footballer of the Year following his European Cup triumph with United.