Mr Nixon blames international tourists in vans not equipped with toilets for most of the problem and is concerned rules preventing campervans from freedom camping might be introduced.
"We love being able to just find ourselves somewhere for a night or two . . . and I'd really be severely disappointed if someone managed to get laws passed to prevent that happening."
Mr Nixon bought his $120,000 vehicle four years ago and believes only vans that have toilets should be allowed to freedom camp at such places as Katiki Beach, north of Dunedin.
"You go walking through the bushes down to the beach and there's tissues . . . and human faeces and it stinks.
"But there's no toilets along there anywhere."
After a recent overnight trip to the Brighton coast, Mr Nixon returned home with two boxes of bottles he collected from his camping site.
He believed it was not only campers using the area who were dumping rubbish.
"Quite a bit of rubbish there is actually domestic rubbish that people specifically drive out and throw there."
Purakaunui Bay, in the Catlins, had a freedom camping area with toilets and a rubbish skip and, as a result, he had not noticed rubbish or human faeces on the ground there, he said.
