Matt Smith lands the Tardis lands in Trafalgar Square for Doctor Who 50th anniversary episode

The Tardis came to Trafalgar Square as Doctor Who stars Matt Smith and Jenna-Louise Coleman were spotted in the landmark location.

They were filming scenes for the special 50th anniversary episode of the long-running science-fiction show in central London.

The stars were seen with a group of actors dressed as armed police officers while a crane lowered the Doctor's trusty police box to the ground.

Show bosses have stayed tight-lipped about the plans for the special episode which is rumoured to be a 3D extravaganza filled with familiar faces from the history of the show.

Last week, they confirmed that former Doctor Who actor Christopher Eccleston had turned down the chance to appear in the episode.

The actor, who played the ninth reincarnation of the Time Lord when the BBC revived the show in 2005, met writer Steven Moffat to discuss the anniversary.

A BBC spokeswoman said: "Chris met with Steven Moffat a couple of times to talk about Steven's plans for the Doctor Who 50th anniversary episode. After careful thought, Chris decided not to be in the episode. He wishes the team all the best."

At least one living former doctor - David Tennant - will return for the one-off show after it was announced he and Billie Piper, who played companion Rose Tyler for two series, will join the current Doctor, played by Matt Smith, in the programme.

But fans might still get the chance to see Eccleston's portrayal of the Doctor as show bosses are rumoured to be planning to use old footage of previous incarnations for the special show.

PA