Jakarta :  Indonesia s forestry ministry Thursday said it has launched a probe into the suspected poisoning to death of 12 elephants in Sumatra.

Novianto Bambang, director for conservation and biodiversity at the ministry, said there was strong suspicion that the elephants that died in East Aceh and the Tesso Nilo National Park in Riau since March were poisoned, Xinhua reported citing the Jakarta Globe.

He said forensic laboratory tests are going on. The statement came after an elephant was found dead in Riau. Villagers said the carcass, without its tusks, was found in a decomposed state Wednesday. The director said even though the tusks of the dead elephants were missing, it did not necessarily mean that the killings were for the ivory.

He said the tusks may have been cut intentionally to create the impression that they were done by elephant tusk hunters, but they may have been poisoned because they were considered pests. The number of Sumatran elephants in the wild has dropped dramatically in the past four years.

The International Union for Conservation of Nature says the species is now critically endangered, one step away from extinction.

There are an estimated 2,400-2,800 Sumatran elephants remaining in the wild, down from the 3,000-5,000 reported in 2007.