Sir Elton John with Katy Perry at his Oscar-viewing party. Getty Images
The 'Rocket Man' hit-maker has previously battled an addiction to the illicit substance but has been sober for over 20 years and has no problems avoiding temptation because he just leaves events if he knows drugs are there.

He said: "If I ever find myself in a situation where there are drugs, I can smell the cocaine. I can feel it in the back of my throat, that horrible feeling of taking the first hit of cocaine. And I leave."

Elton and his partner David Furnish became parents to son Zachary via a surrogate mother in December 2010 and the 65-year-old singer admits the little boy has changed his outlook on life.

The star admits he used to be a "lech" who stared at men and women as he passed by them in a car, but since becoming a father, his focus has shifted and he now studies their children.

He explained: "[I think], 'Who's that kid? What's he wearing? What's his mum pushing him in?' ... It's just changed the way I think, all for the better, thank God."

Elton and David take Zachary everywhere with them and say he is a very "happy" little boy.

He told USA Today newspaper: "Zachary has brought to David and me the most incredible pleasure, and he's brought us the most incredible sense of responsibility and love.

"He comes with us everywhere. He loves traveling. He loves people. He's just a happy-natured boy."