BBC to reveal new 'Doctor Who' on Sunday in live show LONDON (Reuters) - British public broadcaster the BBC will reveal the 12th actor to play the lead role in its long-running "Doctor Who" science-fiction television series in a special live broadcast on Sunday. The half-hour show will feature an interview with the next Time Lord, who travels through space and time battling all manner of malevolent monsters, ranging from new computer-enhanced horrors to the now decidedly creaky-looking Daleks, survivors of the early shows from nearly half a century ago. "The decision is made and the time has come to reveal who's taking over the Tardis," executive producer of the TV series, Steven Moffat, said in a BBC statement on Friday. Actor Matt Smith, who has played the role since 2010, said in June he would be bowing out in this year's Christmas special. His announcement sparked speculation about who might take over, with actors Peter Capaldi, Ben Daniels, Rory Kinnear and Ben Whishaw among the bookies' favorites. "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," said BBC drama controller Ben Stephenson. 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. The series will mark its 50th anniversary in November with a special episode that will see the return of some old faces, including David Tennant and Billie Piper. "Doctor Who Live: The Next Doctor" will be on BBC One at 1800 GMT on August 4 and simulcast on BBC America. Reporting by Paul Casciato; editing by Stephen Addison