"They wanted to do shooting for the film on the press day for the play I'm in at the Old Vic which meant me being in the theatre all day. So, initially I couldn't do it.

"So it looked as if the part was gone until the director came back and said that he wanted me for the part. They have now arranged new dates for the shooting which will take a couple of days.

"I'm delighted as I've a lot of friends and family and their children who all love Harry Potter, so it's lovely to be involved.

"I've never seen any of the Harry Potter movies or read any of the books," admitted Michelle, who now plans to watch the films and read the books in preparation for her part.

"It's not a very large part, maybe three or four scenes which will take just a few days filming. But it's very nice indeed for me."