I'm looking for a supplier of the sort of cam lock which requires the use of a square section key to open. I think it's called a service key.
The idea is to use a pair of these locks on each of the under-eaves access panels in my loft. The cam would open into the frame that the panel sits in.
I've seen things such as the panels which hide lavatory cisterns in office washrooms secured with them but I've no idea what to ask for or Google for.
TIA
Richard