Deckhands were so scared of a far north Queensland fisherman they jumped in crocodile and shark-infested waters to escape, police say.
A 47-year-old man has been charged with 46 offences including torture and slavery after allegedly abusing his young staff on his fishing boats for years.
The fisherman has been accused of threatening and assaulting deckhands, even withholding food and water, since 2020 in Queensland's remote Gulf Country.
Six former employees - five men and a 25-year-old woman - have so far come forward, with some allegedly taking drastic action to evade the "well-known" fisherman.
"Some of those complainants were in such fear of their lives and wellbeing that they actually dived from those boats and swam through crocodile and shark inhabited waters to the mainland to get off the boat," Acting Inspector Jason Chetham told reporters.
"In some cases persons who were employed as deck hands on those fishing vessels were abused, they were assaulted, they were forced to work without wages or were forced to sleep on the open deck of the boat."
Insp Chetham said the deckhands would have felt very vulnerable on a boat with the fisherman, who was described as a "large individual", in croc and shark inhabited water.
"Karumba, it's a relatively isolated part of Queensland. If you've ever been up there it's not the kind of place you want to be in water," he said.
"They were young people working on those boats, trying to earn a living and we allege the conditions were terrible for them.
"Once you get out on the boat there's not many options about to what to do (to leave) - some took very drastic steps."
Six former deckhands have come forward but police believe there may be more.
"We have a very real belief that there are others out there," Insp Chetham said.
"We are happy to sit down with them, take our time and hear their story."
Detective Sergeant Bradley McLeish said police would not tolerate threats to potential witnesses.
"Victims who may be subject to harassment or intimidation in relation to speaking to police are assured that all offenders will be held accountable for their actions," he said.
"Anyone making threats to potential witnesses or victims can expect a visit from detectives very soon."
The man was charged on Wednesday after police said they searched a Karumba address and four fishing boats, locating an illegal firearm.
The Karumba fisherman faces a string of offences including 18 counts of common assault and five counts each of torture and slavery.
He has been remanded in custody and is set to appear in Cairns Magistrates Court on February 9.