BUKIT WANG BURMA, Malaysia — Among the debris of wood, bamboo and plastic tarpaulin at an abandoned camp in the dense jungle here lies a coffin-size cage made from sticks tied together with rusted barbed wire. Next to it, an enclosure that could have held dozens of people also bristles with barbed wire. And over a ridge, the police have started unearthing bodies from shallow graves.
The police in Malaysia have said little about the grim discoveries at desolate camps like this one on a hillside near the country’s border withThailand. But what was left behind here suggests that the camps were busy holding stations for migrants under the control of ruthless, sophisticated human trafficking rings.
The Malaysian government on Tuesday took reporters on a two-hour trek through a buzzing jungle to view this camp in the state of Perlis, in the country’s far north. It is one of several where investigators say they have identified a total of 139 graves believed to hold the bodies of migrants, including members of the Rohingya minority fleeing religious persecution in Myanmar.
Not far across the border, in Thailand’s Songkhla Province, the Thai authorities have uncovered graves containing at least 36 more bodies.
A crackdown in southern Thailand on these human trafficking networks is believed to have triggered the regionwide crisis this month in which thousands of migrants were abandoned by smugglers and stranded at sea. More than 3,000 have landed in Malaysia and Indonesia in recent weeks, and the International Organization for Migration appealed on Tuesday for $26 million to help them.
Muhammad Bahar, a detective with the police in Perlis, said officers exhumed a body on Tuesday from one of 37 primitive graves discovered near this camp in Bukit Wang Burma. He said it was too early to draw any conclusions about the identity of the dead person or the cause of death.
“Another forensic team will confirm later,” he said, standing near the exhumation site, where other officers worked with shovels and hoes. “We have to let forensic do their job.”
But the scene appeared to add weight to reports that migrants smuggled across Southeast Asia by traffickers had suffered extreme brutality. The lower part of the camp was dominated by what appeared to be a holding pen made from wooden poles crisscrossed by barbed wire. On higher ground, a dilapidated watchtower looked over the settlement, which also had a trash pit and a large water tank, suggesting that the site could have been used to hold hundreds of people.
Those who have studied human trafficking said thesyndicates often supplemented their smuggling operations with ransom and extortion schemes. Relatives of those smuggled into Thailand are often called and ordered to transfer large sums in exchange for the freedom of their relatives, according to advocates for the migrants and the migrants themselves.
“They beat you and tell you to call home and come up with the money,” Jeffrey Labovitz, chief of mission of the International Organization for Migration in Thailand, said by telephone. “It’s a ruthless business mentality.”
The trafficking rings demand payments as high as $3,000 to release their clients, who are sometimes starved and abused to put pressure on relatives to come up with the money, according to Alistair D. B. Cook, a research fellow at the S. Rajaratnam School of International Studies at Nanyang Technological University in Singapore.
“Extortion isn’t the word for it,” Mr. Cook said. “The alternative is death. It’s worse than extortion.”
The camps are out of the way, but they sit along a major trading route that links Singapore and the Malaysian peninsula with the rest of mainland Southeast Asia. The route is a hub of legitimate trade as well as a transit point for illicit drugs, smuggled fuel and Malaysians seeking libertine pleasures in freewheeling Thailand.
The Malaysian home minister, Ahmad Zahid Hamidi, said on Tuesday that investigators were examining whether forestry rangers in the densely wooded border region had colluded with human traffickers, according to Bernama, the Malaysian news agency. Some forestry officers have already been detained, he said.
Khalid Abu Bakar, the inspector general of the police in Malaysia, said Monday that the camps were believed to have been occupied since 2013 and that two of them were abandoned only two to three weeks ago,according to Bernama. He said the public disclosure of the suspected graves “proves that the Malaysian government is transparent and not hiding any information involving human trafficking issues.”
But some advocates for Rohingya migrants said the abuses had been largely ignored.
“We hear about families waiting for people to come here, who they never hear about again,” Zafar Ahmad bin Abdul Ghani, the president of theMyanmar Ethnic Rohingyas Human Rights Organization Malaysia, said in a telephone interview from Kuala Lumpur.
“Malaysia needs to investigate Rohingya who have died on the border with Thailand,” he added. “Maybe they also need to investigate the enforcement departments in Malaysia. Have they done enough to enforce and investigate? How can the traffickers cross the border in this area?”
In Wang Kelian, a nearby settlement of paddy fields, some residents said the migrants sometimes appeared and begged for food or cash before moving on by foot. “We know they come through to Malaysia for work, for safety, for family,” said a resident who gave only her family name, Halimah. “But it is shocking for us, too, to learn about how they are treated in the camps.”
Malaysian officials have said little about how these camps and trafficking networks could have existed, undisturbed, for years. But investigators on the Thai side of the border say the camps operated with the help of local officials, Thai law enforcement officers and residents. Nearly 70 Thai police officers have been transferred from their posts as part of the crackdown.
Last week, a former government official whom the authorities described as a kingpin in the smuggling operation surrendered to the Thai police. Patchuban Angchotipan, who had evaded capture for more than a week, is the former chairman of the provincial administration in Satun, a Thai province where smuggling camps were discovered this month.
In what the police say is a measure of the money involved in human trafficking, the authorities froze more than $2 million of Mr. Patchuban’s assets. Among other businesses, Mr. Patchuban owned companies that ran speedboat and ferry services in the Andaman Sea, which were believed to have been used to transport migrants.
Mr. Patchuban, who is known by his nickname, Ko Tong, has been charged with colluding in human trafficking, illegal detention and abduction for ransom.
In an interview on Tuesday, Police Gen. Aek Angsananont, the deputy commissioner of Thailand’s police force, said the trafficking rings generally smuggled Bangladeshi and ethnic Rohingya migrants on boats into Thailand and brought them over land to Malaysia.
General Aek, who is leading the investigation in the smuggling rings, said the police have obtained arrest warrants for 77 suspects. Of those, 46 have been arrested, he said, and the rest are “on the run.”
He added that the crackdown had the support of the highest levels of Thailand’s military government and that the police were “clearing the mountains” along the Malaysian border of trafficking operations.
The crackdown began this month when a Rohingya man filed a complaint at a police station in southern Thailand, saying his nephew was being held for ransom. The police investigating the case discovered the mass graves on the Thai side of the border.
The authorities have not disclosed how the individuals found in the graves died, and some bodies were so badly composed that the cause of death may never be known. A doctor at Songklanagarind Hospital in southern Thailand said that medical workers were close to completing autopsies and that the police would soon reveal results.
Increasingly, the Rohingya leaving Myanmar have included women and children. And clues amassed by the Malaysian police from the border camps suggested that children had been among the inmates. Among photos of items recovered from the camps, one showed a pair of mildewed, pink children’s sandals.