I discovered there was no warning bulb in the socket so fitted one.
Then found out that it was permanently on, even though all bulbs function.
I have subsequently, replaced the ECU that drives it and the scenario has become;
Ignition on light on, start engine light off, which is what it should do, however, first touch of the brake pedal and it is back on again.
All bulbs on the car are working and none are aftermarket LED's.
The only thing I can think it could be, is how the importer has wired up the rear fog light function to a brake light.
Anyone with any ideas?