New Doctor Who unveiled live on TV
The new Doctor Who will be unveiled live on television on Sunday.
The identity of the latest timelord has been a closely-guarded secret and BBC boss Ben Stephenson revealed executives at the corporation have been using the codeword "Houdini" to stop it getting out.
Viewers will see Matt Smith, who has played the role since 2010, bow out in the Christmas special and be replaced by the latest doctor.
This Sunday's half-hour show, which goes out on BBC1 at 7pm, will be presented by Zoe Ball and feature interviews with Smith and executive producer Steven Moffat as well as guests including celebrity fans and some previous incarnations of the science-fiction hero.
Mr Moffat said: "The decision is made and the time has come to reveal who's taking over the Tardis. For the last of the Time Lords, the clock is striking 12."
BBC drama controller Ben Stephenson said: "We can't wait to unveil the next Doctor with everyone live on BBC1 on Sunday night. Amongst all the speculation and betting, there has been lots of fun and intrigue at work as we've been using the codename Houdini as a decoy.
"It's the biggest secret in showbiz, even those working with the new Doctor on other projects at the moment have no idea they are in the presence of the 12th incarnation."