Big names announced for Doctor Who Easter special

Just days after relative unknown Matt Smith was unveiled as the next Doctor Who, TV bosses have confirmed that two of the small screen's biggest names have been lined up to appear in the Easter special of the cult sci-fi show.

Fresh from attempting to crack the States with her lead role in the doomed remake of 'The Bionic Woman', Michelle Ryan will join the Doctor on the forthcoming 'Planet of the Dead' episode, playing a "mysterious" character called Lady Christina de Souza, the show's producers have announced.

Confirming the news, the former EastEnder said: "I'm a huge fan of 'Doctor Who' and very excited to be joining David Tennant and the 'Doctor Who' team.

"It is such a fantastic show and I can't wait to be started!"

Just as enthusiastic at securing the show's new signings, executive producer and writer Russell T Davies explained that he was delighted to have "one of the most sought-after actors in the country".

"As always the script is being kept strictly under wraps however we can reveal that Lady Christina is a woman with a mysterious past who's going to have a huge impact on the Doctor!"

However, both Ryan and Davies have remained tight-lipped over speculation that Ryan could be set to join the show on a full-time basis as the part of assistant to Matt Smith's Doctor in 2010.

Also set to appear in the one-off episode is Lee Evans, with the funnyman to take on the role of Malcolm - a man, the producers explain, "whose life becomes connected to the Doctor's under extraordinary circumstances".

This latest episode will be one of four to feature prominently in the nation's TV guides over the next couple of years before David Tennat steps down, possibly to concentrate on his stage career.

Meanwhile, bosses at the BBC have also confirmed that filming of a new series of the popular comedy 'Big Top' has started, with stars such as Amanda Holden, John Thomson and Tony Robinson resuming their roles as members of a travelling circus.

Announcing the show's return to the TV guides, BBC One controller Jay Hunt stated: "'Big Top' is a heart-warming family comedy with real potential to capture the imagination of the BBC One audience. I am delighted it will be part of the new raft of comedies on the channel," he said.