British comedian Catherine Tate has been confirmed as the newest companion for eccentric tv time traveller, Doctor Who. Tate will fill the gap left by Freema Agyeman, who currently plays medical student Martha Jones in the BBC TV series.

Agyeman leaves after the series 3 final, 'Last of the Time Lords', but the BBC says she'll make a "triumphant return" in the mid-season series 4, as well as starring in 3 episodes of Torchwood (Captain Jack Harkness' spinoff show, starring John Barrowman).

Catherine Tate is no stranger to the world of Doctor Who, having appeared as runaway bride Donna Noble in the show's 2006 Christmas tv special, 'The Runaway Bride'. She'll reprise her role for all thirteen episodes of series four.

David Tennant is expected to stay on as the Doctor for the fourth series, along with a number of high profile guest stars.

It was revealed earlier this week that pop singer Kylie Minogue will guest star in this year's Doctor Who Christmas special, 'Voyage of the Damned'. Shooting for the episode is scheduled to begin in Cardiff, Wales later this month.