The car park verge was covered in litter this morning, including a discarded toothpaste tube.
The campers were clearly visible to staff, customers, and any other tourists heading to the supermarket.
"It's a sad reflection on Greymouth."
Grey District Council said today it could help if Countdown or The Warehouse complained about the littering on their property.
However, freedom camping laws covered public land, not the privately owned supermarket car park, although they could be charged under the Litter Act.
"It is up to the landowner to have them trespassed," environmental services manager Ian Davidson-Watts said.
Earlier this month, Hokitika tourist operator Jacquie Grant spotted someone "piddling" outside the post office after spending the night in a van.
Website rankers.co.nz suggests places to freedom camp all over the West Coast, including Jellyman Park, Cobden, the Whataroa River and the Waita River, just north of Haast.