A pod of seven sperm whales have been discovered dead on a beach in an unusual mass stranding in south Australia.

The whales, which measure up to ten metres in length and can weigh up to 50 tonnes, were discovered by residents at low tide at Parara beach about 90 miles north-west of Adelaide.

It is currently unclear what cause the mass stranding, but a local fisherman suggested they could have been chasing a school of salmon.

Samples will be collected from the whales to try and determine whether the whales became stranded because of illness.