Hollywood stars can now be recreated so perfectly through technology that actors are drawing up wills to control how their digital selves perform long after their death, the Oscar-winning British special effects team behind the film Gravity has said.

The revelation comes after another British company, CereProc, helped to produce an audio recording of John F Kennedy “delivering” the speech he was due to give on the day in 1963 that he was assassinated.

According to the special effects company Framestore, however, technology now allows for much more. Sir William Sargent, Framestore’s chief executive, says special effects have broken the equivalent of the four-minute mile, which is to make a digital human that convinces viewers it is real.

The result, he said, was that Hollywood is toying with ideas that feature older actors, like Sean Connery and Harrison Ford, playing opposite digital creations of their younger selves. “The only thing stopping that is cost,” said Sir William. “But whether it happens in one year or five, it will happen.”