Fiji police are investigating the local shipping company over the allegations.
Police said they received a complaint from a member of a group of foreign seafarers, who had alleged abusive treatment by their employer Goundar Shipping Limited.
About 20 Filipino seamen were recruited - some as long as three years ago - by the company which runs interisland services.
But the group claimed Goundar had abandoned them and that they are owed back-pay and fares home.
The seafarers sought the help of the International Transport Workers Federation (ITF) who called for a thorough inquiry into Goundar's operations.
ITF inspector Sarah Maguire told RNZ Pacific while the federation welcomed the police investigations, it was important the police address the full list of allegations against the shipping service.
Maguire, who is based in Australia claimed the Filipino seamen were 'lured to Fiji to operate an ageing ferry fleet under false pretences'.
Maguire said the seafarers later found the company had lowered their wages, they were working in unsafe conditions and they did not have a return ticket home.
This was required under Fiji's immigration laws.
"But when they arrived in Fiji, the company informed the seafarers that they would be paid 60-70 percent less than what they were promised," she said.
Workers tricked: union
Maguire said the workers they had spoken with made similar allegations about a discrepancy between the salary promised in the contract they had signed in the Philippines and what they received once in Fiji.
"The seafarers have been tricked by Goundar Shipping into flying to Fiji to operate and maintain its fleet of passenger and cargo ferries with promises of decent wages and conditions.
"Goundar is also refusing to send them home as agreed."
Last week, the ITF revealed Goundar had fired and abandoned three seafarers after the workers began asking local union representatives about their rights.
Maguire said ITF investigations uncovered that staff at Goundar Shipping tried to confiscate a number of seafarers' passports and other documents upon beginning work with the company.
The ITF alleged the company would not allow the seafarers to work until they did so.
Withholding travel documents and forcing persons to work under threat are both offences under Fiji's human trafficking laws.
The seafarers claimed they had lodged a complaint with the Labour Ministry in September 2020 but nothing was done.
"We welcome news of a police investigation into Goundar Shipping after so many months of inaction from the Fijian authorities," Maguire said.
"But it is important that any investigation addresses the full list of allegations against Goundar.
"We're talking human trafficking, slavery, deception, labour law violations, intimidation, the list goes on.."
According to Maguire, Goundar also cut the workers' food rations down to bread and tea, pushed them to work unsafe hours and did not consistently pay them for their overtime.
Maguire said the calculations showed the seafarers had been paid as little as 75 cents per hour for the hours they had worked.
At least one seafarer, a cook, she said, had a reported take home pay of just 40 cents per hour.
"He was paid for seven hours per week despite working 98-hour weeks.
"The ITF estimates Goundar Shipping owes the seafarers more than $US100,000 in unpaid wages.
"These illegal pay cuts kept these seafarers too poor to afford tickets home. They're trapped there - working for a man they despise. And if they complain, his company sacks them and dumps them at the nearest port with absolutely nothing."
Goundar Shipping did not respond to a request for comment.
But last year, the company reported crewing challenges due to the Covid-19 pandemic.
In November, the company announced that four of its 10 vessels were idle and anchored because of insufficient manning.
The company told one newspaper it had lost over $1 million and couldn't get Filipinos over because of the pandemic.
"We just have to wait for Covid restrictions to be lifted so that we can get our overseas crew.
"We don't have any crew at the moment to man the four vessels."
Hiring local crews not an option for ferry service
When asked why the company was not hiring local crews when Fijian seafarers were being recruited for foreign ships, the company said it was a matter of preferences.
It told the newspaper everybody wanted to go on foreign vessels.
Meanwhile, the Human Rights at Sea an international NGO which has been working to highlight the seafarers case said they were concerned.
The group said it had been in touch with the seafarers through the humanitarian organisations providing direct welfare support in Fiji.
"It is clear they have been grossly let down by their employer and cast aside with little if no consideration as to the impact the loss of employment and wages will have on them and their families," said chief executive David Hammond in a statement.
"Unfortunately, this is an all too familiar story. Fortunately, it has attracted international press attention without the case being fully hidden behind the corporate veil."
Suva-based lawyer, Adrienne Ali, was representing the seafarers and said following her client lodging the police complaint, Goundar Shipping accused him of theft.
Ali contacted the Philippines Consulate in Wellington on the situation of the seafarers and had been assured the mission would assist its citizens.
Ali said she also wrote to the Fiji Human Rights Commissioner, Employment Ministry and Immigration Department calling for an investigation into the alleged abusive treatment of her clients.
Ali said she was working with the ITF and relevant authorities to get the seafarers safely out the country.
Sarah Maguire agreed, saying the Filipinos had been "working under exploitive conditions for a really long time now and they do need to go home, and they need to go home as quickly as they can".