Matt Smith On Departure From Doctor Who

Matt Smithhas spoken of his difficulty in deciding to quit Doctor Who.

Appearing at Comic Con in San Diego, the departing Time Lord said it had been a "privilege" to play the Doctor and explained: "But I think, when you gotta go, you gotta go.

"It wasn't an easy decision to come to, but I don't know… you can't play it forever."

The 30-year-old also weighed in on the subject of his replacement during an interview with IGN.

"It can be anyone, and that's the great thing about the part. If Helen Mirren did it or if, you know... there's so many female actresses who'd be amazing.

"He's an alien, or she's an alien, it doesn't matter. The doctor is a complete alien. It's why the notion of getting married or cooking scrambled eggs makes him say, 'What on earth are you doing?'"

John Hurt was recently linked with a role in the upcoming 50th anniversary special.