Federal Circuit Court Justice Michael Jarratt??? struggled to imagine a "more egregious" case of worker exploitation.

For six months, Aru, 53, picked fruit at farms dotted across Queensland as part of a federal government low-skilled Seasonal Worker Program. He was paid less than $150 in total.

Some days, he ate no food, save for some of the tomatoes he picked.

"I have never before experienced working a full day without even a cup of tea," Aru told investigators from the Fair Work Ombudsman.

But Aru was among the lucky ones. Thirteen of his fellow workers didn't receive a single dollar for their work in Australia.

The story of these 22 men from Vanuatu is compelling not only because of the sheer brazen nature of their exploitation, which was described by Justice Jarrett in a judgment as "appalling".

But, significantly, the exploitation occurred as part of the Australian government's own program to bring seasonal workers from Pacific islands. The scheme is supposed to fulfil the need for low-skilled labour in Australia's horticulture sector and to deliver aid in the form of employment to struggling Pacific nations. It's also supposed to be the nation's most exploitation proof.

But these men's treatment reinforces the fear that some had of the Seasonal Worker Program (SWP) that it would mimic the notorious practice of "blackbirding", in which up to 62,000 Pacific islander people were forced into slavery in 19th-century Queensland.

Aru and 21 other Vanuatu workers were recruited in May 2014. A Queensland businessman, Emmanuel Bani, had earlier travelled to Vanuatu to spruik participation in the scheme. He ran two labour hire companies in Queensland, including the benign-sounding Maroochy Sunshine, and had cultivated a network of farmers seeking workers.

Bani needed to pass muster to access the SWP. He was assessed as an "approved employer" by the Department of Employment, Education and Workplace Relations and the Immigration Department. It appears all this required of Bani was an acknowledgement that he understood Australian workplace laws. In return, he was able to sponsor workers on 416 business visas.

Meanwhile, in Vanuatu, Aru signed up to the SWP because "he would be able to earn good money to support his family and help pay school fees". His fellow workers, including Jacob Malsokle, had similar aspirations, with some taking loans out from the National Bank of Vanuatu to cover airfares and expenses.

Aru and Malsokle both paid an agent in Vanuatu a $1500 fee to ensure Bani sponsored them. It took Aru five months working in Vanuatu to save this fee.

Bani promised the 22 workers a briefing from Fair Work Australia and the Australian Workers Union upon arrival in Brisbane, but this never occurred. In late July 2014, the men were taking to Helidon, a tiny town in the Lockyer Valley and told to wait. Little food was supplied, with evidence later given in the Federal Court that what was provided "was never enough and did not last long".

It was worse when Aru and his fellow workers began labouring on a nearby farm. Sometimes they were given only one meal a day.

In August, the men were bused to the Bundaberg region, working sporadically on farms. Aru was staying at a backpackers' hostel called "Cellblock", and some days consumed only a piece of bread and some water. Sometimes his fellow workers slept on chairs or, if travelling to a farm several hours away, in a bus arranged by Bani.

When the workers began to query Bani about their abject conditions, he threatened to refer them to the police and have them deported.

Aru and his fellow workers were, in the words of Justice Jarrett, "rescued" in September by the South Sea Islander Association.

Thirteen of the 22 men had not received a dollar for their work, the others were paid a total of $1100 (between $50 to $150 each) by some of the farmers they worked for.

"Most received no wages and while in Australia they had to endure appalling treatment by Mr Bani, who had received payment for the labour undertaken by the employees and payment from the Australian government pursuant to [the SWP]," Justice Jarrett found.

"This case concerns the serious exploitation of vulnerable foreign workers lured to Australia by false promises ... Employees were at times deprived of the appropriate basic living standards expected in Australia."

The judge found it "difficult to imagine more egregious conduct" than that displayed by Bani, and warned of its potential to undermine confidence in the SWP.

Aru returned to Vanuatu in debt, having been exploited and threatened.

Justice Jarrett has ordered Bani and his firm pay Aru and his fellow workers almost $80,000 in outstanding wages, although it's unlikely they will ever see the money. The $227,300 fine issued to Bani by the Federal Court is also unlikely to ever be paid.

In his judgement, Justice Jarrett warned Bani would more than likely "continue to ignore industrial laws".

One of Bani's companies, Pacific Crop Harvesting, is still running a website which spruiks its ability to supply contract farm labour at "minimum costs, maximum rewards".

As the Fair Work Ombudman's three-year Harvest Trail Inquiry is likely to report when it delivers its landmark findings later this year, there is plenty of demand for such an offer.

Aru's story begs a major question for the government and the agencies and taskforces responsible for policing worker exploitation. If such an extreme example can occur as part of a supposedly regulated visa work program, what is happening to the nation's army of undocumented workers?

The case also throws into relief again the work of unscrupulous labour hire agencies who are linked to farms supplying major supermarkets and grocers across Australia.

In the past few months, Fairfax Media has revealed cases of serious worker exploitation at farms in Victoria, NSW and South Australia, with the latter case also involving the SWP.

The Fair Work Ombudsman, which prosecuted Bani after several workers complained, said the case revealed "harrowing" exploitation.

"The workers spent much of their time in remote and isolated transient accommodation, sometimes sleeping in a bus on the side of the road or on chairs in a bedroom," said acting Fair Work Ombudsman Michael Campbell.