A forest ranger allegedly stabbed his friend then killed himself while tracking wild tigers in Thailand.

Khathawut Klomkliew was said to have attacked his colleague, Phakphum Makern, with a knife during a research expedition in a forest in Thong Pha Phum district, Kanchanaburi province on November 25.

The two were both employees at the Khao Laem National Park and were installing cameras to observe the behaviour of Bengal tigers in the wild as part of a project with the Zoological Society of London (ZSL).

Researcher Prinya Yenjit, who was part of the mission, alleged that Khathawut was incoherently mumbling about his wife before the incident happened. The disoriented forest ranger then reportedly lunged at the sleeping Phakphum, wounding him with a blade while the team members were resting.

He also allegedly fired a gun that jolted the others awake, causing them to flee to safety. They reportedly came back after an hour to find Phakphum bloodied with chest and knee injuries, while Khathawut had apparently shot himself dead with a firearm.

Park chief Thewin Meesap said he radioed for assistance to rescue the team after being notified of the incident.

He said: ‘There was a disturbance during the field trip into the forest. We co-ordinated with the military helicopters to bring the dead man and the wounded man out of the forest.’

A military helicopter was sent to retrieve the victims. The arranged airlift failed, however, since the site was too deep in the forest. Officers had to trek there on foot to clear an area for landing.

Khathawut’s grieving family and friends expressed doubts about his death, saying he had no reason to kill himself. Police said they would interview the other rangers after they have been rescued from the forest.

Colonel Nipon Sisuwan from the Thong Pha Phum district police station said the investigation into the death and alleged attack were still ongoing.

He said: ‘There was an argument between the two men before one was stabbed and one died. We are interviewing colleagues and relatives to find out why this happened.’