Daniel Radcliffe used Cameron Diaz photo to guide him during Harry Potter flying scenes, says Tom Felton

Harry Potter star Tom Felton has revealed the unusual way Daniel Radcliffe did flying scenes while filming the franchise’s movies.

In Felton’s new memoir, Beyond the Wand: The Magic and Mayhem of Growing Up a Wizard, he wrote that Radcliffe used a photograph of his celebrity crush, Cameron Diaz, to help guide him on where to direct his gaze while filming scenes on a broomstick.

The actors would perform the flying scenes – for the fantasy sport Quidditch, for example – in front of a green screen, with the background getting added in in post-production.

“The broomstick was a metal pole fitted with a deeply uncomfortable bike saddle,” Felton, who played Draco Malfoy, wrote.

“There were stirrups for your feet and a harness to stop you falling. They strapped you to the pole, so you couldn’t fall, and they had a more elaborate see-saw device to move you up and down, left, and right. They blew fans in your face to make it look as if you had the wind in your hair.”

The young stars were then told to look at “a tennis ball on a long pole” as the flew.

“When the first assistant director shouted ‘Dragon!’ or ‘Bludger!’ you had to look at the tennis ball like it was, well, a dragon or a bludger,” Felton recalled.

He explained that, because sometimes there were multiple tennis balls in scenes, each actor was asked to look at their own personalised tennis ball.

“We chose pictures of something or somebody close to our hearts,” he wrote. “Daniel Radcliffe had a picture of a particularly beautiful Cameron Diaz.”

Meanwhile, Felton, who is a fan of fishing, had an image of a “beautiful carp”.

In a recent interview with The Independent, Felton talked about his memoir, JK Rowling, fans “shipping” him and Emma Watson, and knowing when to accept help for your mental health.