26 dead bodies have been removed from a mass grave site in southern Thailand after a second day of digging near a human trafficking camp deep inside the jungle.

The decaying corpses are all that remain of illegal migrants from Myanmar and Bangladesh who were brought to the country via vast trafficking networks which activists say are 'out of control'.

More than 30 people are thought to be buried in shallow graves at the chilling site in Songkhla province, just 300 metres from Malaysia.

How they died is still a mystery but a Thai police chief made the ominous prediction they suffered a 'violent death'.

The Sadao district where they were kept prisoner is a known stop-off for traffickers who can hide away in the remote woodland before taking their captives across the border and beyond.

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Chilling: 26 dead bodies (pictured) have been recovered from a mass grave site near a human trafficking camp in southern Thailand

Death: The decaying corpses (pictured) are all that remain of migrants from Bangladesh and Myanmar

Investigation: As forensic teams (pictured) try to figure out how they died, a police chief says they may have suffered a 'violent death'

Horrific: It is not known how the migrants died but a Thai police chief has made an ominous prediction that they suffered a 'violent death'

Corpses: Authorities believe identifying the dead bodies (pictured) will be a lengthy process because relatives need to travel from Myanmar and Bangladesh to give DNA samples

Squalid: The traffickers would keep their now-deceased captives (pictured) in cages until they received the money for their transport across the border

Remains: The site where corpses and bones (pictured) are currently being dug up was a known stop-off for traffickers before taking the refugees across the border and beyond

Illegal immigrants - many of them Rohingya Muslims - make the dangerous journey by sea to escape religious persecution and find jobs in Malaysia and Thailand.

Their captors keep them trapped in bamboo cages until they received their ransom money in full, while sick and disabled migrants were abandoned to die when traffickers were forced to leave.

One man and two children survived the tragic fate that befell their fellow migrants and were taken to a nearby hospital for treatment.

Authorities have known about the camp's existence for quite a while, the Deputy Commissioner General of the Royal Thai Police.

Aek Angsananont said: 'We heard news about this camp and tried to find it many times but because it was deep jungle, it was very difficult.'

The police believe the horrific deaths were due to 'a disagreement within the human trafficking trade'.

Exhumed: Rescue workers have removed around 30 dead bodies (pictured) from the camp which could have housed as many as 300 migrants at one point

Exodus: Many of those who died in the makeshift camp near the Malaysian border (pictured) made the dangerous journey by sea to escape religious persecution and find jobs in Malaysia and Thailand

Hike: Soldiers, policemen and rescue workers trekked for 50 minutes up the mountainous jungle to find the graves (pictured)

Cause of death: Forensic teams have been examining the skeletons removed from shallow graves covered by bamboo after a second day of digging

Decay: Human remains (pictured) were retrieved from a mass grave at the abandoned human trafficking camp just three hundred meters from the border with Malaysia

Skull and bones: Authorities have known about the existence of the camp where the dead bodies were found for quite some time

Remote: The site where bodies are being exhumed (pictured) for a second day is a known stop-off for traffickers who can hide away in the mountainous jungle

Prison: More than 30 people are thought to be buried in human trafficking camp (pictured) in Songkhla province, just 300 metres from Malaysia

Identifying the victims could take a long time because their relatives would need to travel from Myanmar and Bangladesh to give DNA samples, Police General Jarumporn Suramanee said.

The abandoned camp - hidden on a high hill deep inside a Thai jungle - was strewn with the shoes and clothing which once belonged to the migrants who died there.

Jarumporn added: 'From the evidence given by witnesses who were in the camp, we believe there was violence here and people died from the violence.'

Human Rights Watch has now called for an independent investigation headed by the UN to find out exactly what took place there.

Its Asia Director Brad Adams said: 'The discovery of these mass graves should shock the Thai government into shutting down the trafficking networks that enrich officials but prey on extremely vulnerable people.'

No escape: The refugees would be trapped in bamboo cages until their captors received the ransom money in full

Brutal: The illegal immigrants who died in the camp - many of them Rohingya Muslims - made the dangerous journey by sea to escape religious persecution in Bangladesh and Myanmar

Probe: Human Rights Watch has now called for an independent investigation headed by the UN to find out exactly what took place in the human trafficking camp (pictured)

Examination: Police have cordoned off sections of the human trafficking camp (pictured) where the migrants were left to die in cages and pits

Recovered: Rescuers spent a second day carrying away the bodies (pictured) of dead migrants in Songkhla province