The Department of Conservation has issued a warning to pet owners after they say results show two blue penguins found dead by New Plymouth’s Breakwater were victims of dog attack.

Little blue penguin. Source: Department of Conservation

The dead penguins were found last week near Port Taranaki.

DOC says that "another blue penguin body was reported nearby but the people who found it threw it in the water and it wasn’t recovered."

Massey University necroposy results found the two penguins were victims of dog attack, with DOC saying it's also likely the third penguin was killed by a dog.

DOC Senior Ranger Biodiversity Callum Lilley says "there have been 42 blue penguin deaths due to dog attack documented in the Taranaki region since 2007.

"That’s just the ones we know about – it could be a fraction of the actual number."

The latest incident has led to a warning to pet owners from DOC.

"It is really frustrating that the message just isn’t getting through to people – you must control your dog at all times. It should preferably be on a leash. If it is off-leash it should be close, well controlled and near the waterline."

Under the Wildlife Act, owners of dogs who hunt or kill absolutely protected wildlife could face prosecution.