Olivia Newton-John couldn't "speak properly" when she met Robert Redford

Asked when she was most starstruck, she said: "That's easy! When I met Robert Redford. He's always been my favourite actor.

"I went to a dinner in Santa Fe and I was seated at his table.

"I was a bit unable to speak properly, which is very unlike me.

"There was an auction for a poster from 'Butch Cassidy and the Sundance Kid'. I told him that when my sister and I were in New York and I was all of 21, we went to see 'Butch Cassidy' and I fell in love with him and my sister fell in love with Paul Newman.

"We got the poster and put it up in the hotel.

"We went out one night and my sister got very drunk. We got back to the hotel. I put her in a cold shower and put her to bed. The only thing she could focus on to keep her from passing out was that poster.

"So I bid on the poster, won it, and on the bottom Robert Redford wrote, 'Haven't I seen you in a hotel room somewhere?' I still have that poster."

The 'Grease!' actress had her first role in a school stage production when she was just seven years old and she's "impressed" she can still remember her line.

She told Empire magazine: "My father was a master at Ormond College in Melbourne and my brother was at the college.

"They did a play and I don't remember what it was but I know it had something to do with Jesus because I had a crush on the guy playing Jesus.

"I was maybe seen. In the opening of the play, I stood up and my line was, 'And the darkness was on the face of the deep.'

"I didn't know that was from the Bible at the time. My first ever line on stage. Impressed I still remember it."