None of 'Harry Potter' cast feature in new West End play 'Harry Potter and The Cursed Child'

He told the Daily Record newspaper: "I would be very surprised if any of the original cast were to feature because the last thing they would want to do is go back to something they did 10 years ago.

"We've been working with actors since the beginning of this year, but the characters are the stars of this - so I don't think we'll be saying a hot Hollywood actor will be playing Harry Potter."

John also revealed that he has known 'Harry Potter' author J.K. Rowling - whose real name is Joanne - since she was a struggling writer and single mother in Edinburgh over 20 years ago.

He explained: "I first met Jo years ago when we didn't know who each other was. I had just started at the Traverse in Edinburgh, and now and again I would see a woman with a pram writing in longhand in the cafe. She'd write in Nicholson's, The Elephant House and the Traverse cafe.

"We knew each other to nod at. I'd be having meetings with writers and actors and I'd see her. Eventually we'd say hello to each other and a year later - bam! Then I realised that's what she was doing."

While the cast is yet to be announced, producers Sonia Friedman and Colin Callender are said to be on the lookout for the leads and informal auditions are currently being held.