With few exceptions, they were all young men. With no exceptions, all had the same story.

They were having trouble finding work. A man - sometimes a stranger, sometimes someone they had worked with at a previous job - would come up to them and say he could get them work in the southeast of the country. Once there, they were beaten, feet and hands bound, then put on a ship where they were beaten again whenever they dared to ask any questions.

This was the tale of 81 Bangladeshis who are now in a government hall in Takua Pa in Thailand's southern Phang Nga province. In this section of the Andaman coast - famous among beach vacationeers, rock climbers, and divers - these men were held captive in the jungle by people who authorities believe planned to sell them to work on rubber plantations and fishing boats.

In some ways, it's not a new story. Rohingya fleeing persecution in western Myanmar have for the past few years been discovered being held in the jungles of southern Thailand. The seafood industry that thrives in this area is notorious for its use of bonded labour.

But this latest rescue marks a significant milestone in a shift that has been taking place for a while.

As boats of Rohingya refugees kept turning up and more of them would be found in the jungles, one thing became noticeable. A number of them were, in fact, not Rohingya - they were Bangladeshis.

The Rohingya were embarking on a dangerous - often fatal - boat journey across the ocean towards an uncertain future to escape ethnic cleansing. It says a lot about the desperation felt by poor Bangladeshis that they joined in on this risky trip.

The thing about these journeys though, was that the 81 Bangladeshis had not come along of their own volition. They were deceived. They thought they were going to Malaysia to find employment - instead they ended up stuck working on fishing boats in gruelling conditions for little or no pay. This is the standard human trafficking story in this area.

What is frightening about this latest group is that they were physically forced into the trade. The traffickers are no longer content to exploit the desperation of people to undertake this journey. They are kidnapping and selling humans.

The difference between human trafficking and slavery is often debated - but this looks more and more like an old-fashioned slave trade.