When was it announced the Tennant and Piper would be returning to the show ?
The first of these was the behind - the - scenes series " Doctor Who Confidential " which began airing on BBC Three in conjunction with the 2005 series and returned for a new set of episodes in 2006 ; each episode focuses on elements of that week 's " Doctor Who " episode , and the series has continued alongside all stories since 2005 .