The deaths of two little blue penguins in suspected dog attacks on Wellington's south coast has prompted a warning to dog owners to keep a close eye on their dogs.

Wellington City Council says a member of the public found the two dead little blue penguins at the airport end of Lyall Bay beach last week.

Late last month another penguin was found dead at nearby Moa Point.

"From the bite marks on all three carcasses it appears the penguins were attacked and killed by dogs," the city council's biodiversity co-ordinator Myfanwy Emeny said.

"A lot of people might not realise penguins have a very strong smell and are very attractive to dogs. Small dogs can even get inside their nest boxes and destroy the eggs and kill the chicks," she said.

"It is the nesting season now and adults are feeding their chicks in the nest. If an adult penguin gets killed or injured by a dog, it is likely their chicks would starve."

The council is urging dog owners to keep their dogs on a leash or, if they're in a dog exercise area, keep a watchful eye on them.

Under the Dog Control Act, the owner of a dog that attacks or kills wildlife can be fined up to $3000 and the dog can be destroyed.