Officials said the incident occurred after a baby elephant slipped over the waterfall in central Thailand's Khao Yai National Park, reports BBC.

Two other elephants were also found struggling on a cliff edge nearby, and have been moved by Thai authorities.

The waterfall, known as Haew Narok (Hell's Fall), has a history of similar incidents.

A herd of eight elephants died after falling in 1992, in a case that brought national attention.

Thailand's Department of National Parks, Wildlife and Plant Conservation (DNP) said officials were called to the scene on Saturday at 03:00 local time (20:00 GMT on Friday) when a group of elephants was blocking a road by the waterfall.

Three hours later, the body of a three-year-old elephant was spotted near the base of Haew Narok, and five others were discovered nearby.

Khanchit Srinoppawan, chief of the national park, told the BBC that the two remaining elephants were being monitored.

Edwin Wiek, the founder of Wildlife Friends Foundation Thailand, said the pair may have difficulty surviving as elephants rely on their large herds for protection and finding food.

The incident could also take an emotional toll. Elephants have been known to display signs of grief.

"It's like losing half your family," Mr Wiek told the BBC.

"There's nothing you can do, it's nature unfortunately," he said.

Around 7,000 Asian elephants remain in Thailand, with more than half living in captivity.