The BBC is the British state owned TV and Radio; the national Broadcasting for Great Britain. We don't know which one it is because there are legal issues with revealing his Identity, everybody is wondering who it is. This situation reminds me of a movie scene in the movie called 'The Thing' by John Carpenter from the 80s; The crew realise that at least one of the crew members is not human so they devise a test, they poke each crew member's blood sample with a hot needle to see if it tries to move. None of the crew are certain who is the alien and who is human because the alien organism imitates it's victim perfectly.
I'm very familiar with the BBC platforms, I play BBC radio 4 when I'm in the kitchen cleaning, they have some very interesting debates sometimes. I also watch movies on the BBC iPlayer on the TV. Sometimes I watch mystery documentary shows and things like that. There is a lot of stuff you can choose from on there.