Tennant set for Doctor Who spin-off

07:30 27 May 2009

David Tennant is to appear in the hit CBBC show Doctor Who spin-off 'The Sarah Jane Adventures' this autumn.

Tennant will make his appearance over two episodes in the new 12-part series which starts this September, the BBC has announced.

However, viewers will not simply get a short-lived glimpse at the travelling Time Lord, according to its makers.

"It's not just a cameo from David. This is a full-on appearance for the Doctor as he and Sarah Jane face their biggest threat ever," said Russell T Davies, executive producer of both shows.

The show follows the adventures of the investigative journalist Sarah Jane Smith - one of Doctor's former companions.

Elisabeth Sladen who plays the feisty character, starred in the original Doctor Who series opposite Jon Pertwee and Tom Baker between 1973 and 1976.

Doctor Who babes The Time Lord's sexiest sidekicks

Sladen said: "It's fantastic news that Sarah Jane is going to spend some time working with the Doctor again and is testament to just how successful this CBBC series is."

Tennant will be hanging up the keys to the Tardis after three more specials, starting with 'The Waters of Mars' in November, after which he will be replaced by Matt Smith as 11th Doctor next year.

Meanwhile, the BBC has hinted that Doctor Who may be set for the big screen, with a script already in development, however said it is likely to be a long way off.