Robin
It's a chenille, on close inspection it seems the stain has been completely removed from the pile but remains in the backing. The discolouration around the stain is, as you suggest, the stain spreading on loosening. I cleaned the whole arm with fabric restorer before I left and rinsed with fib fab rinse
There were two simililar spots on one step of the wool stair carpet which I treated the same and also could not be fully removed, expectations weren't high for these, being on wool
It's probably my lack of experience which allows me to feel slightly defeated when stains aren't completely removed, but I'm sure as I learn and improve my techniques I will have a more realistic outlook on these things!
Customer skiing, back next week so when I've spoken to them I might put a quick post on but meanwhile thanks for your help and advice
Steve
Thanks for that, I haven't used it before but will suggest it to customer next week
Regards, Phil