It was in a fairly modern house - last 15 years I'd say
When I examined the wall it consisted of a layer of plasterboard and directly behind that was about 8cm of solid pink foam then breeze blocks. No gap or wooden studs.
The cupboard had been screwed to the plasterboard using metal plasterboard fittings - not surprised it came off - could have killed a child.
I sorted it using by drilling into the breeze blocks and putting 8mm studs in with resin but what's the approved type of fixing for this type of wall? Rigifix?