Catherine Tate confirms 'Doctor Who' exit

Doctor Who star Catherine Tate has confirmed she will leave the show at the end of the next season - and believes David Tennant might be joining her soon after.

BBC News reports that Tate, who will be reprising her role as companion Donna Noble in the fourth season, told Jonathan Ross on his Radio 2 show that she will not be staying on. She also suggested: "I think it's maybe David's last series."

However, Tate said that Tennant will "possibly" play The Doctor in the three specials commissioned for 2009 by the BBC. The lack of no new season that year is believed to have been caused by Tennant's theatrical commitments next year, which will greatly hinder his availability for filming.

The future of Doctor Who is assured until 2010, following a BBC announcement in September that the time-travelling drama will return for a full fifth season.