James Phelps accidentally broke the director's ribs during the filming of 'Harry Potter and the Goblet of Fire'.

The 35-year-old actor - who starred as Fred Weasley in the blockbuster fantasy films alongside his twin brother Oliver as George - injured Mike Newell during a play fight whilst filming the fourth movie in the series.

The 79-year-old filmmaker recalled: "We were doing the scene when Fred and George are rejected from entering the Tri-Wizard tournament. We had these wigs on and beards on what looked like old men, and Mike said, ‘OK, I think you guys are going to be really annoyed with each other, I think you should have a good fight about this.'"

Speaking on the HBO special 'Harry Potter 20th Anniversary: Return To Hogwarts' - which celebrated the release of the first film based on the best-selling books by acclaimed author J.K. Rowling - Mike explained that he intervened to encourage the boys to fight which left him in agony.

He said: "These two were sort of prissying about at it and I said, ‘No, come on boys, it’s a fight’.

"I was a tubby 60-year-old gent at that stage and I really shouldn’t have done it.

"I remember gripping him round the waist and trying to fling him about and so forth and I cracked a couple of ribs.

"I was in absolute agony from then on, but of course, the wonderful thing was that I’d made a complete twit of myself and everybody felt much better for that."