Ten endangered pygmy elephants have been found dead this month in Borneo and are thought to have been poisoned, conservation officials said Tuesday.

Wildlife authorities in Sabah have formed a task force together with the police and WWF to investigate the deaths.

Sabah wildlife department director Laurentius Ambu said they received a report last Wednesday of four dead pygmy elephants in the Gunung Rara forest reserve.

But officials were "shocked" to find another four of the animals, a rare sub-species of the Asian elephant, dead or dying after inspecting the area for two days, he said.

"Early this year, two highly decomposed elephant carcasses were found in the general vicinity of where these eight animals were found. We believe that all the deaths of these elephants are related," he said in a statement.

Sen Nathan, the department's senior veterinarian, said in the statement "we highly suspect" the animals died due to poisoning after finding severe ulceration and bleeding in their digestive tracts.

"It was actually a very sad sight to see all those dead elephants, especially one of the dead females who had a very young calf of about three-months-old. The calf was trying to wake the dead mother up," he said.

Masidi Manjun, the state's environment minister, vowed to take tough action.

"If indeed these poor elephants were maliciously poisoned I would personally make sure that the culprits would be brought to justice and pay for their crime," he said in the statement.

There are fewer than 2,000 Borneo pygmy elephants, which are smaller and have more rounded features compared to normal Asian elephants, left in the wild, according to authorities.

Activists warn that pygmy elephants are fast losing their natural habitat to deforestation and human encroachment on Borneo, a vast island shared by Malaysia, Indonesia and Brunei.

- AFP