Weird noise under full or near full lock

Theres a grinding squeeking noise coming from my steering when i put it under full or near full lock, any ideas?

have you got power steering?

I have something similar to this as well, I notice it the most when going round a roundabout!

If you've got power steering then check the colour of the fluid, it should be a red-ish colour. If it's not you might need new fluid. It's worth doing this as it'll only cost a couple of quid. Another thing to check is the power steering belt is tensioned properly

One other thing, does it do it with the car stationary? If it does then get someone to turn the wheel back and forth while you listen down by the wheels for the source in case it's suspension or steering rack related. I recently traced a similar noise on a Felicia down to both spings being broken up the top