Doctor Who star Matt Smith admitted he had become "symbiotic" with his co-stars Karen Gillan and Arthur Darvill because they had spent so much time filming together.

Speaking at Comic-Con, the actor said he spends "every waking hour of the day" in "nine month" stints with Karen and Arthur when they are working.

The actor also commented that he never argued with his fellow Doctor Who actors.

Karen Gillan, who plays Amy Pond as the Doctor's companion and Arthur Darvill, who plays her husband Rory, will not be back for the shows next season.

The series is one of the BBC's most lucrative exports and airs in the United States on BBC America.