CHARLOTTETOWN -- A necropsy has found that several dead seal pups were still young enough to be nursing when they were bludgeoned on a beach in Prince Edward Island last the weekend.

Pierre-Yves Daoust, a wildlife pathologist at the Charlottetown-based Atlantic Veterinary College, said Friday the necropsy on 10 grey seal pups also determined that they all had severely fractured skulls.

"There was no evidence of metal fragments that could have suggested that they were shot, so the obvious conclusion, I would suggest, is that they were clubbed," said Daoust.

Students from the school found a total of 50 dead grey seals on Murray Beach on Sunday, just a day after seeing them healthy in the same area.

Daoust said the pups were not clubbed as part of a seal hunt. He said some may have taken several seconds -- or longer -- to die.

"It's very possible that some of the animals were not killed quickly," said Daoust. "It certainly was not done by professional sealers and ... the animals were wasted."

The pups were only a few weeks old and were still nursing, said Daoust.

"The stomachs of some of those seals were filled with milk," he said. "It doesn't paint a very pretty picture at all."

The federal Fisheries Department is investigating.

Humane Society International of Canada is offering a $1,000 reward for information leading to a conviction in the case.

"It is devastating that these nursing pups ... were beaten in this brutal fashion and left to suffer in agony," Rebecca Aldworth, the society's executive director, said in a statement.

"This is criminal cruelty, and the people responsible need to be identified and brought to justice."