There are fears hundreds of endangered yellow-eyed penguins are being killed in fishing nets.

Forest & Bird say the fishing industry can't be trusted to accurately report penguin deaths in their nets.

New figures released under the Official Information Act show 14 penguins died in the 12 months from October 2015, but Forest & Bird's CEO Kevin Hague said only one of the deaths was reported by the industry.

He said the rest were reported by Ministry for Primary Industries observers on fishing boats and they are on only three percent of the fleet.

"The yellow-eyed penguin - an iconic New Zealand penguin that is on the cusp of extinction - it turns out that fishing by-kill may be a significant factor in the decline of that species," he said.

"That leads us to believe that it may be the case that literally hundreds of penguins are being killed and their deaths are not being reported by the industry, and the Ministry has failed to take effective action."