Picasso has front near side creaking sound.

Annoying constant creaking from n/s on any road surface that isnt smooth, local Citroen specialist suspected the damper but settled on replacing its top rubber mount, getting the car back it was delightfully quiet for 3 trips out, about 100 miles in total then gradually the creaking returned, the garage once again checked the damper but with nothing obvious admitted defeat and sadly wrote the job off, once again the noise had gone but only temporary, it has now returned and I suspect it as being the wheel arch liner all along, has anyone had a similar experience which can confirm what I am now suspecting ?

My garage is at a loss with this noise but thinking about how each time he has investigated ,involving wheel removal ,the car has been quiet for a couple of days before it slowly returns, I suspect the wheelarch liner, I can live with that