A fisherman faces torture and slavery charges after being accused of a string of offences against deckhands, including withholding food and water.

The 47-year-old man has been charged with 46 offences after police launched an investigation in far north Queensland’s Gulf of Carpentaria.

Queensland Police Acting Inspector Jason Chetham said at least six deckhands were allegedly abused and assaulted on board the man’s vessel.

Some allegedly swam through crocodile and shark-infested waters to escape the boat.

“They unfortunately worked without wages, they were forced to sleep on the open deck of the boat,” Chetham said.

“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.”

Chetham said police so far alleged there were five male victims and one 25-year-old female victim. They believe there could also be more, and have appealed for others to come forward.

“We are alleging they were certainly exploited and manipulated and, in some cases, physically assaulted by this individual,” he said.

“Young people working on those boats, trying to earn a living… we’re alleging the conditions were terrible for them.”

The man is also accused of withholding food and water.

Queensland Police began an investigation last year after reports a man allegedly threatened numerous deckhands on board his fishing vessels.

Detectives searched an address and four fishing boats last week in the Gulf town of Karumba last week. They allege an illegal firearm was among the items found.

On Wednesday, the Karumba man was charged with 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 will appear in Cairns Magistrates Court on February 9.

Police have appealed for “witnesses and victims” to come forward.

“If you have information that could assist this investigation, we want to hear from you,” Detective Sergeant Bradley McLeish said.

“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.

“Anyone making threats to potential witnesses or victims can expect a visit from detectives very soon.”

Karumba is an isolated town in Queensland’s Gulf Country. It has just 550 residents.

-with AAP