Perrin Brown looks at a poison 1080 pellet, one of many he says he found on and off a track between Supply Bay and Balloon Loop which is outside DOCs 1080 drop zone in the Kepler mountains.

The Department of Conservation is investigating whether 1080 poison pellets were put in a non-designated drop zone in the Fiordland National Park to make the department look bad.

Te Anau DOC operations manager Greg Lind made the suggestion on Sunday.

However, a Te Anau man who has lodged a complaint with DOC over its 1080 poison drop in Fiordland's Kepler mountains, Perrin Brown, has labelled Lind's suggestion as laughable.

"It's a typical reaction from DOC. This is how they cover things up and try to make things go away, with those sorts of statements," Brown said.

DOC used a helicopter to drop 1080 poison pellets on 25,000 hectares in the Kepler Mountains near Te Anau on September 20 and 21.

The purpose of the poison drop was to target the rat population.

Brown laid a complaint with DOC after the drop, saying some of the poisonous pellets landed in waterways and others landed outside of DOCs designated drop zone.

Brown took photos of individual 1080 pellets lying on a walking track, outside of DOCs designated 1080 drop area, near Lake Manapouri on September 24, saying he saw about 50 of the pellets.

The track he found the pellets on, between Supply Bay near Lake Manapouri and Balloon Loop on the Waiau River, was reasonably popular with Manapouri and Te Anau residents, he said.

The pellets would kill a young child or domestic animal if eaten, he said.

A hunter in the same area on September 21 said he had seen helicopters flying overhead that day and later saw 1080 pellets on the ground.

Lind did not appear convinced the pellets found in the non designated drop zone had been dropped by its helicopter, but said he was reserving judgement until an investigation had taken place.

DOC 1080 drops normally resulted in one pellet every 10sqm but DOC had found a higher density of pellets in the area they were not supposed to be in, he said.

"The distribution of the bait is very suspicious."

DOC was now checking to see whether the helicopter had mistakenly dropped the bait outside its designated area or if there were "more mischievous reasons behind it".

If it was planted it would not be the first time it had happened, he said.

Brown, a former commercial hunter, questioned Lind's logic, saying DOCs 1080 drops did not always have an even spread.

Brown also had a go at DOC for dropping the 1080 in waterways and said DOC had been lax in informing the public about the 1080 drop.

Lind, however, hit back.

The major bodies of water, including lakes Te Anau and Manapouri, were kept outside the 1080 drop zone but DOCs resource consent allowed the 1080 to land in the smaller waterways.

"The reason is 1080 rapidly breaks down in water," Lind said.

Immediately after the 1080 poison was dropped in the mountains, DOC staff walked the DOC tracks in the designated drop area and threw any 1080 pellets they found into the bush, he said.

All affected parties and neighbours near the drop area had been informed of the 1080 drop 48 hours and 24 hours before it happened, he said.