In extreme cases, skilled chefs at the Rockpool Dining Group's restaurants are earning as little as $15 per hour some weeks, well below the minimum wage, while working up to 30 hours' unpaid overtime. While chefs are generally expected to work long and unsociable hours, it is a breach of workplace law for an employer to require such excessive unpaid overtime if it pushes wages below the minimum rate of the award, the wages safety net. Loading Separately, company emails seen by Fairfax Media advise workers on how not to record the actual hours they worked, another likely contravention of workplace laws. The investigation has uncovered the underpayments at two of the group's restaurant businesses, Sake and Munich Brauhaus.

Rockpool Dining Group did not respond to specific questions about the ''misleading'' recording of hours nor about the treatment of migrant workers, but a spokeswoman said it was "difficult to comment on alleged documents we have not seen, may be incomplete or falsified’’. ''That said, we take these claims very seriously. It should be noted our employees are remunerated in line with the industry award ... our permanent employees are on annualised salaries, and there are mechanisms in place to review pay annually,'' the spokeswoman said. ''Furthermore, we have policies and procedures in place which clearly outline employee compensation for overtime, including their being able to take time off in lieu.'' Chief executive Thomas Pash declined to be interviewed and Mr Perry also did not respond to requests for comment. Short-changed

Among the Rockpool Dining Group’s 16 restaurant brands are ''premium'' eateries Rosetta and Sake, ''casual and fun'' restaurants including Munich Brauhaus and The Bavarian, as well as its flagship, Rockpool. Saké restaurant Credit:Joe Armao The pony-tailed Neil Perry, who has a column in Fairfax Media’s Good Weekend, is regarded as one of Australia’s best and wealthiest chefs. He opened his flagship Rockpool in 1989. Perry sold his Rockpool Group to Quadrant private equity-backed Urban Purveyor Group in late 2016 for a reported $65 million, becoming the group's chief brand and culinary director and a significant shareholder. Jonathon Pearce, Justin Ryan, Alex Eady, Chris Hadley and Marcus Darville from Quadrant Private Equity. Credit:Daniel Munoz

The private equity-backed group is now heavily indebted and expanding rapidly and, with forecast revenue of $325 million this financial year, is the largest high-end restaurant business in Australia. Not all its businesses have worked out and it closed its high-end Sydney restaurant Jade Temple on Saturday due to poor performance. However, the investigation based on company pay records, internal management documents, pay slips and hourly records provided to workers, has uncovered serious underpayment and other issues. Leaked documents show permanent chefs regularly earn less than $20 an hour and, some weeks, up to $800 per week less than they would under the award. The restaurant award allows management to ''buy out'' penalties and overtime for a 25 per cent higher hourly rate. However, under the buyout, workers must still be paid more than the award overall. Chefs would only need to work between one to five hours a week of unpaid overtime to be underpaid, an analysis by The Age and SMH of hourly and pay records shows. The chefs regularly work 10 to 20 hours of unpaid overtime.

The documents also show that the restaurants keep two sets of figures: the hours actually worked, alongside the hours rostered and paid for. Receipts are given to workers when they clock on and off using a thumb touch-pad. It shows the hours they are paid for - typically eight hours per day. Beneath that on the receipt, the actual hours the staff worked are recorded. This can be up to 14 hours in a day. The excessive hours pushed all permanent, non-management chefs who were listed on the documents below the legal minimum hourly rate.

Management at Sake instructed workers in writing not to record the real hours they worked. Emails obtained by The Age and SMH tell workers not to record the actual hours they worked when applying for days in lieu or when they work on public holidays. Munich Brauhaus at South Wharf, Melbourne. The excessive hours have led to fatigue and workplace injuries at the chain, some chefs say, including workers being taken to hospital for exhaustion and badly cut fingers. "We are not allowed to speak up about our safety concerns,'' a chef said. ''If we did we would not be able to stay in the country as our employment would be terminated." 'Slavery'

Many of the workers at Rockpool Dining Group are migrants, and some have been told that if they want their permanent residency application processed, they must use the company's lawyers. Loading One chef at the group said their visa status made migrants vulnerable to excessive work, significant underpayment and exploitation. They accuse their employer of dragging out their applications for permanent residency and of holding their temporary status in Australia over them. If they speak out or complain, they will lose their job and be forced out of the country, chefs say.

''They’re squeezing us,'' the chef said. "For us it feels like a new age of slavery." University of Adelaide associate law professor Joanna Howe said there were ''endemic'' problems with the design of Australia’s temporary migrant worker programs. ''It gives employers all the leverage,'' she said. ''It gives workers very few options but to acquiesce to these types of demands.'' University of Adelaide law professor Andrew Stewart said the Fair Work Act was unclear about how many hours of overtime was ''reasonable’’. But that did not mean workers should not be paid for that overtime. ''Just because you can be asked to work reasonable overtime doesn’t mean that you don’t get paid for those extra hours,'' he said.

Professor Stewart said audits by the Fair Work Ombudsman of employers pointed to a culture of ''entrenched non-compliance'' when it came to paying legal rates of pay. The Age-SMH investigation is the latest to reveal widespread flouting of Australia’s workplace laws involving some of Australia’s biggest businesses. Last year The Age reported that celebrity chef George Calombaris had underpaid 160 staff more than $2.6 million. George Calombaris underpaid staff at his business. Credit:AAP Recently the ABC reported allegations about unpaid overtime and underpayment at another high-end restaurant business, Shannon Bennett’s Vue de Monde. Vue has denied the claims.

The Andrews government announced recently that, if re-elected, it will introduce laws to make wage "theft" a crime, punishable by up to 10 years' jail. Do you know more? Contact us securely via Journotips Follow Ben Schneiders on Facebook