Two young porpoises and a dolphin have been found washed up dead on a beach in mid Wales.
The three were washed up on Borth beach, near Aberystwyth
Marine wildlife experts have been unable to carry out post-mortem examinations on the animals because they had been dead for some time.
Two of the creatures may have been caught in fishing nets, but the other had probably been killed by a dolphin.
The bodies of the two juvenile porpoise and a common dolphin were found on Borth beach, near Aberystwyth.
Marine strandings co-ordinator for Wales, Rod Penrose, said the two juvenile porpoise and the larger common dolphin were found on Monday.
"We were unable to ascertain the exact cause of death because all three animals had been dead for too long," said Mr Penrose.
"But it's possible the dolphin may have been caught in sea bass trawler fishing nets off Cornwall.
"Every year dolphins get caught off Cornwall when the sea bass fishing takes place. It's possible that the dolphin then drifted up to Wales."
Mr Penrose added that the dolphin had a shattered beak, which was a sign it had been caught in a net.
"One of the porpoise appears to have been caught in a fishing net too, while the other porpoise had rake marks (from teeth) consistent with an attack by a bottlenose dolphin," he added.
Mr Penrose explained that attacks on porpoise by dolphin were doubling year on year.
In January, wildlife experts said harbour porpoises were being killed in increasing numbers by bottlenose dolphins around British coasts, possibly due to competition for food.
The evidence came from counts of porpoises washed up on coasts and from post-mortem examination of the animals.
A lack of fish may be turning the dolphins on their cetacean relatives, some scientists at London's Natural History Museum said.