Malaysian police forensic teams, digging with hoes and shovels, on Tuesday began pulling out bodies from shallow graves found in abandoned jungle camps where an inter-governmental body said hundreds of victims of human traffickers may be buried.

The Malaysian government said it was investigating whether local forestry officials were involved with the people-smuggling gangs believed responsible for nearly 140 such graves discovered around grim camps along the border with Thailand.

The dense forests of southern Thailand and northern Malaysia have been a major stop-off point for smugglers bringing people to Southeast Asia by boat from Myanmar, most of them Rohingya Muslims who say they are fleeing persecution, andBangladesh.

Authorities took a group of journalists to one of the camps, nestled in a gully in thick jungle up a steep, well-worn path about an hour's walk from the nearest road, where a Reuters witness saw the first body removed on Tuesday afternoon.

Malaysian police said on Monday they had found 139 graves, some containing more than one body, around 28 camps scattered along a 50-km (30 mile) stretch of the border in the northern state of Perlis.

Joel Millman, a spokesman for the International Organisation for Migration (IOM), told a news briefing in Geneva that the body's representative in the region "predicts hundreds more (bodies) will be found in the days to come".

THAI CRACKDOWN

The grisly discoveries in Malaysia followed the uncovering of similar graves on the Thai side of the border at the beginning of May, which helped trigger a regional crisis. The find led to a crackdown on the camps by Thai authorities, after which traffickers abandoned thousands of migrants in overloaded boats in the Bay of Bengal and Andaman Sea.

"We don't know if there is a link between the Thai camps and Malaysia camps," Phuttichart Ekachan, deputy chief ofThailand's Provincial Police Region 9, told Reuters.

"It is possible that because of the Thai crackdown some of the camps moved and some of them (migrants) then walked over or escaped to the Thai side. It is possible but it isn't something we have been able to confirm."

Thousands of Rohingya Muslims are ferried by traffickers through southern Thailand each year, and in recent years it has been common for them to be held in remote camps along the border with Malaysia until a ransom is paid for their freedom.

The IOM's Millman said the largest camp was believed to have had a capacity of up to 1,000 people.

"If an individual's family did not pay, those staying long in the camps were tortured, beaten and deprived of food," he said.

State news agency Bernama quoted Malaysia's police chief, Inspector General of Police Khalid Abu Bakar, as saying that the camps were thought to have been occupied since 2013, and two were "only abandoned between two and three weeks ago".

Khalid told reporters on Monday that police had been "shocked by the cruelty" of the camps, where he said there were signs of torture.

OFFICIAL COMPLICITY?

The scale of the discoveries has raised questions about the level of complicity by officials on both sides of the border.

Malaysia's Home Minister Ahmad Zahid Hamidi said on Tuesday that initial investigations revealed links between forest rangers and smuggling syndicates, Bernama reported, adding that some had been detained by police as part of the probe.

"We suspect some of them were involved...but we are working with the forestry department in terms of enforcement as they are supposed to carry out enforcement in the area," he was quoted as telling reporters at parliament.

Apparently abandoned in haste, what remained of the camp visited by Reuters reporters was little more than a tangle of bamboo and tarpaulin, but one police official, who did not want to be identified, said it could have held up to 400 people.

A large plastic water tank could be seen, suggesting a degree of permanence.

There were also signs of brutality, including coils of barbed wire around what appeared to have been makeshift cells and a low cage, too small to stand in, that police said may have been used to punish captives.

An official said 37 graves had been found at the site, a few hundred metres from the Thai border. As the police teams began to dig, a large supply of body bags and white cotton shrouds was piled on the ground.

Residents in Wang Kelian, the nearest town on the Malaysian side of the border, said they were used to seeing migrants in the area.

"They are often starving, not eaten for weeks," said Abdul Rahman Mahmud, who runs a small hostel. "They eat seeds or leaves or whatever they can find. It's a real pity and it's sad to see this."