The gruesome discovery of two headless seals on a Lower Eyre Peninsula beach last week in South Australia has prompted an investigation by authorities.
The decapitated New Zealand fur seals were found in varying stages of decomposition near Louth Bay on Thursday afternoon.
The SA Department of Environment is treating the deaths as suspicious and warns there are heavy penalties in place for killing a species protected under the National Parks and Wildlife Act.
"The penalty for killing an animal can be a fine of up to $100,000 or up to two years' imprisonment," a spokesperson said.
The animals included an adult that was badly decomposed and a lesser decomposed juvenile.
Both animals have now been buried.Shark attack behind dead dolphin
Meanwhile, a dolphin that washed up dead on a beach about 320 kilometres to the north-west at Eba Anchorage near Streaky Bay last week appears to have been attacked by a shark.
Streaky Bay senior ranger David Grosse said the juvenile Bottlenose dolphin had sustained injuries to its tail and had been transported to the South Australian museum for further studies.
"Dolphins and seals are on the menu for our top marine predators, sharks, so in this case the death of this dolphin is not unusual," he said.
Natural Resources Eyre Peninsula staff added that it was common to see sea lions on the beach and requested that people did not approach them as it could cause "anxiety and distress" for the animal.