The competition watchdog says that fuel retailers use the real-time service to send price signals to one another.

The insider said head office had already collated much evidence that franchisees were not paying their staff correctly and was aware of the half-pay scam where workers are only paid for half of the hours they worked.



"We see the payroll figures on all but a handful of franchisees and most of the payroll is so low, either the franchisee is working a million hours a week or their staff are getting paid below award," the insider said.

In other developments: former competition czar Allan Fels declared the only way that franchisees could make money was by dudding their staff; a prominent lawyer has threatened a class action and Fair Work Ombudsman Natalie James has called on 7-Eleven head office to examine its conduct.

"I think 7-Eleven need to wake up to the fact that this conduct is persistent and it is a clear pattern and that really it's their moral responsibility, their ethical responsibility to step up and take some steps to do something about it," Ms James said.

The insider said the scandal and subsequent head office scramble had sparked an outcry by franchisees who over the past few days head office has tried to blame for the problem.



"The franchisees are furious. The poor ones are ruined, the ones who bought recently are probably sitting on business worth less than when they bought them, and probably worth less than what they owe.



"The richer ones I have no sympathy for."



The insider's comments came as 7-Eleven Australia announced it would buy back franchises from any franchisee who was not happy with the business.



7-Eleven will also set up an independent panel to be chaired by "an eminent and qualified Australian", though the chair was not named by the company in a statement issued on Monday afternoon.



The buyback could cost 7-Eleven tens of millions of dollars with stores selling for between $400,000 and $1.7 million.



"The key factor here is that the panel will receive, review, and process any claim of underpayment, and authorise repayment where this is appropriate," said 7-Eleven chief executive Warren Wilmot.



However, the review could be hamstrung by the widespread doctoring of timesheets and staff rosters used by franchisees to disguise the real hours staff worked in the store.



Often the only way the wage scam can be proven is by comparing CCTV footage of the stores next to payroll documents and at many stores the footage only lasts for a month.



On Monday, former consumer watchdog Mr Allan Fels slammed the company's model, saying the only way franchisees can make a living is by ripping off their workers.



"It seems to me that the business model will only work for the franchisee if they underpay or overwork employees," said Mr Fels who led the Australian Competition and Consumer Commission between 1995 and 2003.



He also called on the federal government to provide an amnesty to international students caught up in the half-pay scam.



"A lot of people, students and so on are afraid to come forward, probably a lot of franchisees are afraid to come forward, so it's a big problem.



"We need a systematic solution to it."



He said the government could offer amnesty for a period of time and then make it clear after that the law would be strictly enforced.



His comments come as Levitt Robinson Solicitors principal Stewart Levitt said he was preparing a class action against 7-Eleven Australia and its American parent , 7-Eleven Inc, on behalf of ripped-off workers and disgruntled franchisees.