I have an annoying permanent seat belt indication on the dash even when key is out..

i have done the following but light persists:
I have checked, as best i could, the seat buckles and have cleaned them
removed battery to reset the BCU/ECU
Seems this is driving towards a faulty occupancy sensor (seat pressure pad on the passenger seat) however this is embedded in the seat itself and i cant locate any wiring loom under the seat
I also cant find any wiring diagrams relating to this...

Any ideas on how to resolve this issue..?