I could be wrong here, but on the side of the red light cameras, most of them say GATSO (like normal speed cameras) and hence a lot are used for speeding fines as well. It also says near where I live (where there is one traffic light camera) 'Speed Cameras and Traffic Signal Cameras'. This leads me to believe they can be multi-purpose.
I'm afraid to say I think you will be receiving a NIP in the post (3 points and 60 quid) I had a nightmare about red light camera and them flashing me. Paranoid!
Once I was driving home through Leed and I was going through a traffic cam. And I was approaching the lights, and they changed when I was only a few metres away. Typical as there was no-one else around!! I tell you, I did the biggest emergency stop, I've ever done in my driving career. The bastards aren't getting me! *Touch wood*