The union claims Hazeldene's hires up to 200 workers on 417 and 457 visas, as well as permanent residents, bused to Bendigo from Melbourne every morning.

The arrangement with two labour hire companies has been in place for up to five years, but the union only raised concerns in the last two years when the foreign workers were expanded beyond boning tasks.

NUW Victoria secretary Gary Maas said union members at the Lockwood site had been getting in touch more and more over the issue.

"I find it extraordinary that Hazeldene's would need to bus in more than 200 people each day," he said.

"It's ridiculous that they cannot source the kind of skills they need locally.

"These are good jobs. They deserve to be done by people who are trained properly."

Mr Maas alleged the contracted workers were being paid below the minimum wage of $21.79 per hour.

A Hazeldene's employee, who wished to remain anonymous, said the contracted staff were working between 10 and 14 hour shifts every day.

The employee said Hazeldene's had about 40 foreign workers a few years ago, which had increased to 200 in 2015.

"It's changed the way it operates for permanent workers, they are shifting people around the site," the employee said.

"People are worried. We've seen the contract workers put in place in other areas of the factory apart from just the boning area.

"Their excuse is that they can't fill staff numbers, but I've absolutely had people tell me that they have been rejected for jobs."

Another employee said management had treated newly-unionised workers unfairly.

The employee said Hazeldene's "liked to use the EBA when it suited them, but not when it suits the workers".

The National Union of Workers said it had taken its claims to the Fair Work Commission, among other claims with companies in the poultry industry.

In a statement, Hazeldene's said it had also taken the NUW to the Fair Work Commission for "bad behaviour on site, including breaches of privacy and harrassment of employees to sign up as members".

Hazeldene's "strongly refuted" claims the 417, 457 and other visa staff were being underpaid.

"The NUW's assertions that contractors at Hazeldene's are underpaying staff are unfounded," the statement said.

"Hazeldene's strongly refute any claims that our employment practices are not lawful or unethical."

The statement said Hazeldene's "conducts weekly checks of visa requirements, to ensure validity, for all contractor employees".

The company will meet with Member for Bendigo Lisa Chesters next week to discuss employment and conditions.

She said she remained disappointed that jobs appeared to be going to foreign workers bused up to Bendigo from Melbourne.

"What I will be raising with them is what I raised with them previously," Ms Chesters said.

"I've been contacted by many people who have applied for a job there only to be knocked back.

"Youth unemployment is 18.2 per cent for April. I want to see the jobs offered to locals first."