The logger’s teeth were smashed with the butt of a rifle and his friend fatally shot by a Thai paramilitary force formed to provide support to the Khmer Rouge.

Chakrya*, 24, had ventured across the Dangrek Mountains in Cambodia’s far north to log Siamese rosewood, a species highly prized for furniture manufacturing in China and Vietnam.

Like hundreds of his countrymen, he was caught by the Thahan Phran, Thailand’s paramilitary border protection force.

Its members are also known as the Rangers or “Hunter Soldiers”.

“If they shout for us to stop, we have to do so. If we stop, we will have a chance to survive. If we run, we will be shot,” he said.

“If we stay still, we will just be beaten and jailed. One of us was shot to death because he ran away. On the way [to prison], I was beaten and my teeth were broken, and they did this to make me scared for my life,” he said.

Chakrya would spend the next 17 months in Khantalak prison in Thailand’s Si Sa Ket province – north of Cambodia’s Kulen Prum Tep Wildlife Sanctuary – cramped in a 50-square-metre cell with about 70 others.

“The food was OK, and the job we had to do was to weave [fishing] nets and make tables and chairs.”

The Rangers took Chakrya and his fellow inmates on fortnightly military-style exercises. “We had to respect their discipline,” he said.

“I could not understand the language [the Rangers spoke], but some 200 Cambodians have been there for ages and they interpreted for us,” he added.

About 200 Cambodians were housed in the jail along with Chakrya and his fellow travellers, who all hail from the same village in Oddar Meanchey’s Trapaing Prasat district.

Many of the Cambodian inmates spoke of regular mistreatment by the Rangers and prison authorities.

“We knew that it is dangerous, but we had no choice. We needed to eat or we would starve.”

Formed in 1978 to fight a communist insurgency in northern Thailand, the Rangers were the brainchild of General Chavalit Yongchaiyudh, a Thaksin Shinawatra ally who would later cut a “million-metre” timber deal with Phnom Penh.

The unit’s initial recruits were convicted criminals, and its members later fought in the Preah Vihear temple standoff in 2008 and 2009.

From 1979, the Rangers gave food and weapons to the Khmer Rouge and other anti-Vietnamese factions.

Drafted from Thai villages most affected by the border conflict, “the rangers were not hesitant to take out their frustrations and aggression on the Khmer”, according to anthropologist Lindsay French.

Several attempts to contact the Thai military and Foreign Ministry went unanswered.

An illegal logger who spent time in a Thai prison smokes a cigarette at his residence in Oddar Meanchey province earlier this year. Heng Chivoan

In Chakrya’s village, Sophorn* had been the ringleader of the logging missions.

Also recently released from the same prison, he vowed not to go back to the treacherous trade.

“I would rather live in the Kingdom, because going up the mountain to log makes me little money, but my life was at risk all the time,” he said.

“I was beaten until I arrived at the detention centre. They accused me of using guns to shoot back, but we had nothing apart from rosewood”.

Many who make the same journey are not so fortunate, and although this year the death toll appears to have decreased, dozens of Cambodian timber traffickers have been confirmed killed in recent years.

Despite the hard terrain, hazardous conditions and back-breaking labour, when the loggers returned successfully, they would only make $50 for the slab of hardwood strapped to their backs.

Cambodian military units stationed on the border were the buyers, the men allege.

In China, the wood has been known to fetch upwards of $25,000 per cubic metre.

“They [the military] gain loads of profit, and if we do not sell it to them, we will be detained,” Chakrya said.

Many in Chakrya’s village have turned their backs on the trade, and can now be found in the fields.

The work is hard and the income low, but at least it is safe, they say.

Kuy San, 64, has been to visit her son in the Khantalak prison several times since he was jailed almost two years ago.

She can no longer afford to make the journey to the jail on the other side of the mountain range that straddles the border.

Even when she had the money, she was only permitted 15 minutes with her son.

“We visited him four times during his time in jail, but we can no longer go, because we spent too much,” she said.

Chakrya’s children are none the wiser, and he does not intend on telling them about his ordeal.

“The black-clad soldiers told us not to climb the mountain again, and to find jobs in Cambodia. They said they did not want to kill us, but they had to do so if we returned,” he said.

“I was in jail, but I will never tell my kids about it. I told them I was doing business there. I’ll never go there again.”

General Touch Ra, director of the Working Group on Cambodia-Thailand Border Relations, which oversees military operations along the vast frontier, said that it was difficult to persuade the loggers to give up the trade.

“Sometimes when we told them [to stop], they said even though they would be arrested or killed, they had to climb the mountain, he said.

"Prisons in Thailand might be easy.”

* Names have been changed to protect identities.