Thanks Listerdiesel
I may not have explained myself properly (women driver!!!)
No problem, sometime the smallest things can help with diagnostics.
There are a few things that can cause the problem:
Discoveries have the means to apply the brakes through the ABS in wheel spinning conditions, but obviously not in normal driving. So if this was the case then you would have a fault in the ABS system, possibly identifiable through a fault code.
A failed wheel bearing might be able to allow the hub to cant a bit and cause overheating, but I think you'd hear the noise and realise that there is a problem.
A damaged caliper mounting, perhaps caused by a blow to the hub assy at some time would cause continuous rubbing, and that's the sort of problem you are looking for, but normally the wheel would catch the blow rather than the axle tube end.
A brake pipe that was damaged or blocked would cause the problem, as fluid would not be able to flow and allow the calipers to release properly. 2001 is not that old, so perished flexible pipes that have swollen shouldn't be a problem unless the wrong fluid has been put in there, which is unlikely.
I'd suggest that you need to get the vehicle checked over mechanically by someone who is knowledgeable with Landy mechanicals, and try to pinpoint the fault by elimination. It might be something stupidly simple, but also could be a real sod to track down.
Peter