Not to be confused with Tobe Hooper's shlocky follow up to The Texas Chainsaw Massacre , which I watched and reviewed just a few weeks back, this is a jungle cannibal spaghetti horror film that was done in the late 70s and early 80s to varying degrees of success and which was homaged (not very successfully) in Eli Roth's The Green Inferno.

Janet Agren, who looks every inch the classic B movie actress cast throughout the 70s for her looks and willingness to disrobe (and I'm only saying that because she has no talent as an actor, and because of her propensity in this movie to disrobe), plays rich socialite Sheila.

She was never very close to her activist sister Diana, but the latter's gone missing in the jungles of the Amazon after falling in with what Sheila fears is a dangerous religious cult.

She flies to the area and offers rough, hard drinking mercenary Mark (Robert Kerman, who'd made his most famous film, Debbie Does Dallas, just two years before and was in the midst of a career-long effort to be accepted as a legitimate mainstream actor – how he thought a bunch of extreme horror films would do that is anybody's guess) a huge sum of money to lead her to the religious cult's camp to try and extract her sister, and off they go.

When they find her and the group, led by the soft spoken but enigmatic Jonas, it gradually emerges that he drugs his people into submission, not letting them leave and subjecting them to bizarre rituals of sexual abuse and torture, all of it modelled on the true life Jonestown cult and mass suicide from just a few years earlier.

Just two are the widowed native woman who has to endure sex with three village men who climb on top of her one after the other on her husband's still-smouldering funeral pyre, and another where Jonas smears a menacing looking dildo with snake blood and penetrates a drugged Sheila with it.

Mark can see what's going on and refuses to drink the elixir it's plain keeps everyone under control so he's cast out into the jungle where he has to stay out of the way of one of the cult's many enemies, the local cannibal tribes.

But eventually he has no choice (and because he's already shagged the leading lady), so he goes back to the camp and submits, hoping it buys him enough time to get Sheila, Diana and the raped native girl Mowara (Me Me Lai) – who becomes another ally – out.

Just like in Cannibal Holocaust, the scenes of torture and gore would have been plenty enough to put this movie squarely in the sights of the video nasty censorship movement back in the day, but it's the real scenes of animal deaths (at the hands of both other animals and people) that will make you want to wince and turn away.