Thanks Dave. Beko have subsequently emailed again and say:
“Upon looking into this with our spare parts team, I can confirm that the part you are querying about fits at the bottom of the drip tray just above the motor, the drip tray needs to sit on the sticky pad.”
I assume they mean the condenser/evaporator fan motor, but am hoping there might be some sticky residue to give me a clue. I might be able to get the serial number tomorrow, as it belongs to a relative. I’ll keep you updated.