Thanks for your replies.
We got it down to the starter circuit, so, this morning we disconnected the main feed to see if the 2 amp drain disappeared.
The answer is no really. But when we disconnected a loom of six brown wires from the starter the drain stopped.
So, the starter is sound, but something connected to it is draining the battery. The next thing is to find what these six brown wires are connected to.
Thanks again, Phil