Lost Souls (1980)

Illegal immigrants from the mainland land in HK. Most are arrested on landing but a few escape... which turns out to be very bad luck, as they are picked up by sadistic human traffickers instead.

I've heard this film mentioned many times over the years, usually in the context of "films that are a bit much". Indeed it is! The cast spend much of the film naked and abused. It is an uncomfortable look at the dehumanising ordeals that people with no legal status can be subjected to.

The film can reasonably be accused of exploitation, with many gratuitous shots of nudity (mostly but not exclusively female), but there is nothing erotic about it. Instead, the nudity serves to vividly show the dehumanisation the characters are subjected to. They have no more rights or status than animals in the eyes of their captors.

Apart from a few familiar faces in the roster of bad guys much of the cast seem to be one-time actors... I can see how the experience would not particularly lead one to think "this is something I'd like to do regularly". Or once, really... I wonder if they really knew what they were getting in to.