The parent company of 7-Eleven says it will take action against franchisees flouting the law in Australia.
"7-Eleven is extremely disappointed that a number of franchisees have chosen not to meet their obligations as employers," a statement released on Saturday said.
A joint Fairfax-Four Corners investigation found up to two-thirds of 7-Eleven stores could be underpaying workers.
It also said some franchisees were threatening to report international students to the immigration department unless they worked double shifts for less money.
"We are deeply concerned about the personal impact on affected employees or former employees, and the damage such actions cause to franchisees who are trusted, reliable and responsible small business owners," the parent company said.