One post-production technician, who asked not to be named, said that digital enhancement of actors’ skin had become routine in Hollywood films, but was kept from the public because stars had it written into their contracts that it cannot be discussed. “It is a bit unfair on teenagers watching the film because they can’t expect to have skin like Harry Potter,” he said. “We often go through films erasing crows’ feet on older actresses and spots on teenage actors.”

Vanessa Davies, Radcliffe’s spokeswoman, said that she did not know if the actor’s face had been altered, but added that enhancement was common practice. “No photograph goes from the camera to the screen without something being done to it these days,” she said.