Bennett blamed the behind-the-scenes show's cancellation on BBC cuts, suggesting that it had come to the end of its natural run.
"Doctor Who Confidential had run for six series," he argued. "It was a show about a show. There wasn't much more to say about how they make Doctor Who."
He added: "We are pulling back from pre-watershed TV because of BBC cuts - I've got to make every pound count."
Bennett explained that his focus as head of BBC Three is on "unique programmes".
"I don't want to make loads of extension shows, a la ITV2," he said.
Since assuming the role of controller, Bennett has axed a number of BBC Three series, including The Fades, White Van Man, Ideal and Mongrels.
