French backpacker Rodolphe Lafont has spent a year in Australia on a working holiday visa, employed at a number of farms across the country.
He describes a fruit-picking job in Shepparton, Victoria, as the worst.
He was paid according to how much fruit he picked, rather than the hours he worked and says he was often paid well below the minimum wage.
"You work like 8 hours a day for only 50 dollars. It depends on your efficiency. I am fast but even if you are fast, if the tree is not full or it is not a good day, you don't have a lot of money," he says.
Hostel manager Peter Manziere says he hears horror stories like Mr Lafont's often from other backpackers.
"Everyone has a story. Someone pay them 5 dollars per hour, someone pays them per basket instead of per time. Probably 80 per cent have a bad experience in the farms, yeah."
A new report by two Sydney universities suggests those experiences point to a system that is broken.
Their study surveyed more than 4,300 international students and backpackers working across Australia.
More than half said they were underpaid, with one in three reporting they earned about half the legal minimum wage.
Report co-author Bassin Farbenblum estimates the underpayments are in excess of a billion dollars. "It's clear that Australia now has a large, silent underclass of hundreds of thousands of underpaid migrant workers."
More than 90 per cent of those who experienced wage theft failed to report it to anyone.
Of those who did, two in three got no money back.
Only one in three complainants went to the Fair Work Ombudsman but, even there Ms Farenblum says, more than half of cases resulted in no payout.
"They didn't know what to do, or they found the forms too complicated. A large number were afraid of losing their visa if they came forward and reported wage theft. And a substantial proportion also believed they just wouldn't be successful."
German backpacker Jannik Lasschlott suffered the consequences of speaking out against his employer.
Working on a flower farm in New South Wales, he and 14 other pickers went to Fair Work Australia over their poor living conditions. "They fired on the next day about seven people - the people he knew went to Fair Work, me included."
Employment Lawyer Sharmilla Bargon says fears of losing their jobs or their visas deters many migrant workers from pursuing justice.
"The threat that they might get deported instead of being able to claim a $5,000 underpayment - sometimes much much larger, we have clients with claims of $270,000 - it's just not worth it.”
The study found that poor English was not really a barrier to making a complaint.
In response, the Fair Work Ombudsman says it is considering the report.
