A former worker says drivers for Crust Pizza's Gungahlin store, on Canberra's northside, are not recorded as employees and are paid cash in hand at below award rates.

She believes the majority of drivers hired by the franchise are international students, who are limited to 20 hours per week work, but rarely complain about being underpaid for extra hours, as the extra shifts breach their visas.

The management of the national chain says it has begun an internal review of the claims.

"Thank you for bringing these issues to our attention," a spokeswoman said, adding a review was under way.

The allegations came to light after reports overseas students want more hours of legal work to avoid possible exploitation by employers.

Recently a joint Four Corners and Fairfax Media investigation into 7-Eleven uncovered startling and systemic wage fraud across the country's biggest convenience store chain, including falsification of payroll records and other illegal practices.

The allegations over delivery drivers concern only the Gungahlin store. Fairfax Media does not imply any wrongdoing at other stores in the national franchise chain.

Priya De, a second year arts student at ANU, said she believed the low rates of pay for drivers encouraged speeding.

She says she has been taken off the drivers' roster, effectively firing her, after raising issues with Crust Pizza's Gungahlin manager.

"There's been significant discontent in the store about how staff are treated and their conditions, particularly for their delivery drivers," she said.

"We have tried to resolve issues in-store but to no effect."

Ms De is a domestic student and worked alongside international students delivering pizzas.

"The drivers are paid cash in hand and in piece rates," she said. "We do not get any pay slips. Obviously, we don't receive penalty rates either."

Ms De said the drivers were paid a base rate of $10 an hour, $12 if they delivered two pizzas an hour, $15 for three deliveries and $17 an hour for four deliveries an hour.

"So the highest possible amount you can get paid is below the minimum wage for an adult; it just encourages speeding," she said.

She said it appeared the majority of the drivers hired by the store were international students.

"They're banking on the fact that these students might be too scared to complain or speak out," she said.

Ms Ed said when the claims were put to the store manager, he said, "All of Crust does this."

"I remember his words, they were, 'This is the practice of every single Crust store.' He returned to that again and again," she said.

Fairfax Media contacted the manager of the store for a response to the claims, however the response came from the head office in Southport.

"Crust Gourmet Pizza has become aware of issues relating to payment rates for delivery drivers pertaining to a franchisee in Canberra," the statement said.

"As soon as the company was made aware of the matter a full internal review was initiated.

"Subsequent to the franchisor's engagement, the franchisee has committed to promptly resolve all issues identified.

"The franchisor facilitates induction and ongoing support to ensure franchisees are aware of their responsibilities."

On Friday, Ms De rejected the statement from Crust, saying it was an attempt to minimise the issue.

Lyndal Ryan, ACT secretary of United Voice, said she was present when Ms De presented a list of complaints to the store manager.

"He said, 'This is what Crust does everywhere; why are you complaining? This is what we do everywhere,'" Ms Ryan said.

"Crust's response does not address the fact that the issues were raised months ago and remain unresolved.

"There is evidence that they extend beyond the drivers and beyond one store.

"A company seeking to do the right thing would not allow Priya to be discriminated against for speaking up."