DOC spokeswoman Cornelia Vervoorn said that under the Wild Animal Control Act, the maximum fine for releasing them was $50,000.
Until June 16, there were no known wild pigs in South Westland, she said.
"Historically there have been attempts to liberate feral pigs in various parts of South Westland and most have failed.
"Feral pigs were present for some years in the low hill country behind Lake Paringa, but we believe this group died out or disappeared a few years ago. There have also been feral pigs in coastal forests and dune areas north and south of the Waiho River from time to time."
Pigs are predators, as they will eat almost anything and have an excellent sense of smell.
They have been known to target invertebrates, Powelliphanta snails, kiwi, weka and nesting seabirds.
There are no kiwi in the Paringa area, but if the pigs wandered further south or north they could reach the Haast or Okarito kiwi sanctuaries.
DOC is keen for the public to call in sightings, and also to let staff know if anyone runs one over: "We need to keep track of how many more might be out there."
There are also concerns the pigs could have come from a Tb-infected area, and could introduce the disease to the large area south of the glaciers.
If they did pass on Tb to possums, the may need to be treated with 1080.
Federated Farmers West Coast president Katie Milne, who has received a few complaints, said they were a "timebomb", and she was "fairly horrified".
- The Greymouth Star
