Farm workers were paid just $3 an hour to pick blueberries on the NSW north coast, with the revelation sparking calls for a royal commission into the under-fire horticulture sector.
The McKell Institute has released the results of a three-month investigation into blueberry jobs around Coffs Harbour.
Coronavirus lockdowns led to thousands of backpackers flocking to the region earlier this year with an oversupply of labour contrasting with other parts of Australia.
Natalie Trigwell, 46, lost her home near the NSW town of Nimbin in the bushfires and was living in her campervan when she landed a job picking berries out of pure desperation.
"I went down there and found that I was earning $15 to $20 per day," she says in the report.
Ms Trigwell said fires were so close to the orchard she could no longer see the berries.
With no phone reception, she alleges the contractors wouldn't let her leave.
"And I walked out. I didn't get paid for three weeks' worth of work for that one."
Backpackers and other migrants tell similar stories of exploitation including pay well below minimum wage, seven-day working weeks and other mistreatment.
Sally, another worker, was spammed with almost 2000 messages calling her a "pig" and a "dog" after she asked her labour hirer for the rest of her pay.
A 28-year-old German backpacker earned just $3 an hour during one shift and averaged $6.21 an hour for 17 days of work with a local contractor.
Australian Workers' Union national secretary Daniel Walton said the idea exploitation on farms was limited to a few bad apples needed to be put to bed.
"This shocking new report can be added to the mountain of research indicating that Australian farms have become a hotbed of wage theft, exploitation and worker abuse," he said.
"It's not just Coffs Harbour either - pick a spot on the map and you will find outrageous exploitation."
Mr Walton urged Agriculture Minister David Littleproud to support a royal commission.
Mr Littleproud said he would "never say never" but favours fixing the problem through strengthened and harmonised state laws.
"It's disgraceful. There's no other way you can sugar coat it," he told Sky News.
He said the issue was limited to a small minority, which could destroy the reputation of agricultural work.
The report calls for a crackdown on rogue recruiters, stronger penalties, greater enforcement from workplace investigators and reforms of Australia's visa schemes.
It also argues for new laws to ensure farmers are required to pay a minimum hourly rate.
The investigation found dodgy labour hire companies recruit on Facebook, WeChat and Gumtree and falsely promote fruit-picking as highly paid and fun work.
Lead author Ed Cavanough also observed a cluster of shipping containers converted into four-bed dorms for Pacific Island workers rented at the prices of suburban houses.
Backpackers were paying up to $150 a person to live in nine to 12-person share houses, netting landlords three times the median rent of some Coffs Harbour suburbs.
A Gumtree spokesman told AAP it was strongly recommended job seekers using the platform do their due diligence before considering potential job opportunities.
"This includes finding out as much information as possible about a company before interviewing for and accepting a role," the spokesman said.
Job seekers should use independent resources like ABN Lookup to ensure advertised work is genuine.
Australian Associated Press