Primary Industries, Water and Environment Department spokesman Simon de Salis could not shed any light on the mysterious deaths on Sunday, but said experts would investigate.

Angie Jackson, who reported the case, was walking along the two beaches last week when she found the dead birds.

“They were spread up the beach along the high tide line. It looked like they died at sea and were washed in.

“Along Greens Beach there were about a dozen, and then I counted at least 10 along West Head as well, but there could have been more because I didn’t go all the way up the beach at West Head – it’s quite long.

“Greens Beach and West Head Beach, as far as I’m aware, isn’t actually a home for penguins. They all sort of seem to stay over at Low Head.

“They didn’t have any oil, no bite marks, they didn’t look like they’d been eaten or anything. For the most part they were fairly intact. They just looked like penguins but obviously they were dead.”

Mr de Salis said it wasn’t uncommon in Tasmania to see one or two dead penguins on beaches, but the numbers reported at Greens Beach and West Head Beach sounded “unusual”.

Ms Jackson took to facebook following her discovery, and a number of people commented saying they had also come across dead penguins.

“There have been a few dead ones at Bridport too,” Laura Gregg wrote. “We aren’t sure if they washed up dead or if they were killed once they got to the beach.”

Shannon Perkins wrote, “It’s the same down the West Coast as well”.

A number of other people responded to the post saying they had also seen dead penguins at Sandy Point, Marion Bay beach and Flinders Island lately.