World-renowned physicist Sir Stephen Hawking has said he would consider assisted suicide if he was "in great pain" or felt he " had nothing more to contribute".
The academic, whose life story and struggle with motor neuron disease inspired the Oscar-winning film The Theory Of Everything, discussed it with Dara O Briain in a BBC One documentary which will be shown later this year.
He told him: " To keep someone alive against their wishes is the ultimate indignity.
"I would consider assisted suicide only if I were in great pain or felt I had nothing more to contribute but was just a burden to those around me."
The documentary also includes interviews with Professor Hawking's two children, Lucy and Tim, as well as his colleagues, students and close friends.
Commissioning editor Craig Hunter said: "It's a delight to watch Dara and Stephen's friendship develop with honesty and insight - especially as Dara is fulfilling a childhood dream meeting his hero."