The Senate's job security committee heard more shocking evidence of worker exploitation on Australian farms during a hearing on Wednesday.
Through a translator, Mr Wang said he started working at a Coffs Harbour greenhouse in March 2020 after coming to Australia almost two years earlier.
"While working in the farm, the workers are not allowed by the boss to talk to outsiders about the pay and conditions at the farm," he said.
Despite the job being advertised with a $17 hourly rate, he earned well below that working from 6am until it was dark.
But Mr Wang said he couldn't find a better job because of the language barrier and his lack of friends in Australia at the time.
Australian Workers' Union official Ron Cowdrey told senators about a Fijian worker who died of a heart attack while working on a farm in Berrigan in the NSW's Riverina region.
"The family he left behind - a missus and two young children - they're still struggling in Fiji," he said.
Onion pickers in the area were earning on average between $10 and $11 an hour.
Mr Cowdrey believes some farmers are complicit in exploitation because they are aware of contractors' actions but do nothing to stop them.
"There are a few growers out there that are abiding by the rules, but the majority that aren't are letting those growers down."
Deakin University researcher Elsa Underhill found repeated examples of high levels of exploitation of backpackers from Asia and Europe between 2013 and 2018.
Some were paid as little as $3 an hour.
Dr Underhill said if farmers were willing to pay higher wages, they could risk profits because of supermarket price inflexibility.
"Farmers are in a bit of squeeze," she told the hearing.
The AWU, supermarket workers' union SDA and Transport Workers' Union are in a partnership with supermarkets to try to stamp out problems in the supply chain.
Nationals Senator Matt Canavan said the AWU should focus more on cost pressures farmers faced to make a profit.
"I don't think you'll build wide political support by getting too close to the big supermarkets who have engaged in extremely questionable ethical practices especially over the last decade," he said.