Well, it was an "Anne-Droid" as Rose pointed out. And yes, reading the credits (which I did several times to see if they had got the voice of Big Brother, but I didn't spot him) it was Anne Robinson, and Trinny & Suzannah (from "What Not To Wear"). It's been on (I think) BBC for the last three years or so and seems to be one of the standard repeats out on Discovery Real Time (which was Discovery Home & Leisure until a few weeks ago).

Pretty much as Zander described them.