“Alfonso had a real interest in rougher forms of circus and theatre and didn’t want everything to be CGI. I was asked to do a presentation about what we could do with live magic, which they’d never thought about using before.”

“I felt as if I was auditioning for all of magic – it was pretty nervewracking, and very strange, to have them captive for two hours.”

“I was like a new, very small department on the film, so I had to prove myself. In one of the scenes, all the kids had been to Zonko’s Joke Shop, so the idea was I had to come up with some tricks that were somewhere between the Muggle world and Harry Potter’s magical world.”

The scene in the film sees Harry’s hapless red-haired pal Ron Weasley playing with a jar of handkerchiefs that seem to float around of their own accord. Elsewhere in the film, Paul makes a fleeting cameo as one of the patrons of the Three Broomsticks Pub, making him the only real-life illusionist to appear on screen, and he worked on a series of floating orbs in Hogwarts’ Astronomy Room.

“We’d done all this filming with the Weasley twins (Ron’s older brothers) and Daniel Radcliffe came up to me at the end and said: ‘I can’t believe you’ve taught everybody else how to do magic apart from me’.”

“He had a classroom where we’d do an hour and a half here and there. It was quite funny, because the first thing he wanted to learn was [notorious confidence game] the three-card trick.”

“I taught him some stuff with cards and things like the linking rings, but I’d usually take along a book or some kind of story to give him some kind of sense of the history of it all – he really responded to it, and I even ended up giving him his first ever magic wand.”

“He doesn’t seem to be very different from when we were working on Prisoner Of Azkaban,” Paul says. “But he was never spoilt, which might be because his parents were already in the industry.”