Primo denies the allegations, which were aired on Thursday night on ABC’s 7.30.
Federal Agriculture Minister Barnaby Joyce said it was too early to for the government to act.
“We are talking about allegations and claims and they will get a formal investigation,” Mr Joyce said.
“If they are verified and determined to be the truth it will be taken to the next step.”
The Union’s Newcastle-Northern Branch secretary Grant Courtney said more than 70 per cent of Primo’s Scone workers were on temporary 417 visas, which allowed people to stay and work for two years.
Scottwell International engaged labour hire agencies to source the workers for Primo, he said.
The union had received submissions from 75 workers, stating they were advised by the labour hire agencies to lodge an Australian Business Number (ABN) without being advised to get a tax file number, according to Mr Courtney.
“They are advised by their agent that they don’t have to pay tax," Mr Courtney said.
"Workers should not be provided with ABNs.
"They are backpacker not businesses, they only need tax file number.”
Primo has been contacted for a response.