Disco 2 Squeal from front right wheel

Any ideas? When driving at 60 ish every so often I get a loud high pitch squeal from the front right wheel.
If I touch the brakes it goes away and if I put a small amount of left hand lock on (for example going around a bend) it also stops.
After a while it completely disappears, only to return 10,20 or whatever minutes later.

Any idea where to start looking?

A few year ago we were on our way to France and as we approached Portsmouth there was such a squeal from my Renault Clio that I was worried the wheel bearings were going to totally collapse. We couldn't stop as we had a ferry to catch so carried on down to our gite. A day or so later the squeal had gone. I would suspect wheel bearings or dust in brake pads.

Probably brake pads squealing. You can also get dirt and crap behind the dust shield which rubs alot. Wheel bearings don't sequel, they whur and whine. (usually easy to diagnose by lifting the wheel off the ground and checking for play. Also rotating the wheel with the caliper loosened off and holding the spring is another good way to feel for bearing wear)

Its usually down to a couple things:
- Dirt on or around the caliper area
- Brake shield rubbing
- Brake pads that are worn out
- Discs that are worn out (they usually get a lip on the outer and inner edge which rubs on the pads)