The corporation has been forced to say the show is “safe” after confusion over how many episodes would be filmed for broadcast next year.

Initially, several “specials” rather than a full series were suggested, but now 14 new episodes have been announced, with Matt Smith again playing the Doctor.

Julian Payne, the BBC communications boss, insisted the show is still a ratings hit. He said: “Doctor Who in 2011 has had one of its strongest performances, with 10.3million people tuning in. It is business as usual.

“We are preparing for the new series and Steven [Moffat, head writer] is hard at work on the Christmas show.”

Moffat has denied a claim that scheduling difficulties with the upcoming series of Doctor Who were partly because he was so busy also writing new episodes of Sherlock.