thanks for all of your replies - there is a loft but the bathroom has a false ceiling. I have found what appear to be the two end lamps and the wiring terminates at each so the transformer must be somewhere inbetween.
As for the question how do I know I assume because there is no light then...
I have 9 12V halogen capsules in my new house's bathroom and the transformer has just died. The ex-owner has left the country and is unreachable and I can't fine the transfomer.
I have released all of the fittings from the ceiling and have found two distinct end units but no transformer - can...