Strange noise when reversing on full lock -Peugeot 106

[restoman]

Daughter's Peugeot 106 makes a noise which sounds like a tyre rubbing when reversing on full or near full lock. Having thoroughly examined the car there is no way that the tyres are rubbing so the noise must be emanating from elswhere. Have done all the usual suspension and driveshaft checks and can't find anything amiss.

Anyone got any other ideas?

(Apologies if you've already read this in the engine forum - posted it in wrong section by mistake - doh!)

[Defcon5]

Does it have PAS?