terrible screeching squeaking type noise when turning

Help guys,
When coming back from work today my RR P38 4.6 HSE (1998) started to develop a terrible screeching squeaking type noise when turning. Particularly loud when turning left but also when turning right. No noise when going straight.
I would say it’s like a rubber screeching noise. Kind of a gneeeeeekk coming from front left side. Scaring…
I’ve checked steering pump fluid and it's ok. I had a quick look under the car and looks ok. However I’m not an expert at all.
Any ideas?
Steering pump, steering dumper, hub bearings?
thanks in advance for your help.

Power steering drive belt slipping under load?

Pete

Most likely the drive belt slipping. May be a sign of trouble somewhere in the power steering system, possibly the pump, where the extra resistence of full lock causes the belt to slip. You might want to check the belt tensioner (on the left hand side, just beneath the alternator) has sufficient resistence.

You really don't want that belt to snap, believe me.

Problem solved.
I had my Indi hanging on my front wing while driving reverse with open bonnet and turning the wheel left and right (driving reverse preventing any damage to my bumper if he would have fallen down ). It turned out my steering damper was at the end of his path. Especially the bushes.
Thanks for your help guys.