International students brought to Sydney to boost the NSW economy and who work graveyard shifts cleaning city office buildings are said to be being paid as little as $10 an hour.
Contract cleaning companies are also accused of forcing students and travellers on working holiday visas to accept illegal cash-in-hand payments to keep them "off the books".
The cleaners' union, United Voice, says it has run dozens of cases for students from countries including Nepal, Thailand and Chile who were cheated out of entitlements such as superannuation, sick leave and paid overtime. Other allegations include:
Students forced to pay secret commissions to keep their jobs
Supervisors and subcontractors threatening them with the sack if they refuse to work unpaid hours
Forcing those who take a sick day to pay for their replacements out of their own wages
Companies using subcontractors as a smokescreen to hide unethical practices.
One big cleaning company, the Glad Group, was prosecuted by the Fair Work Ombudsman and is now before the Federal Magistrates Court for underpaying 32 Sydney cleaners, many of them international students, a total of more than $130,000. A penalty hearing is set down for August 1.
It is alleged most underpayments were the result of Glad Group purporting to outsource employment of the cleaners for the fourth hour of their shift at the Deutsche Bank Place building at 126 Phillip Street to another company, which paid them only between $13 and $15 an hour.
Many cleaning companies have signed the union's Clean Start Agreement, designed to reform the industry. Under that agreement, cleaners should be paid $22.80 an hour.
But the union's state secretary, Mark Boyd, said some companies had staff being paid award wages working alongside those paid as little as $10 an hour.
"International students are encouraged to study in Sydney to boost the local economy yet many of them are being ripped off," Mr Boyd said. "In the past two months we've had three separate cases of site managers demanding commissions to keep students on the payroll."
The union was also critical of building owners, who he said must know cleaning contractors were not paying award wages due to the low contract costs. "We know of companies who contract for cleaning work in Sydney based on labour costs of less than $10 a hour," Mr Boyd said.
The Investa Property Group, which owns Deutsche Bank Place, declined to comment on the Glad Group allegations.
The union is calling for a joint state-federal government inquiry into the working and living conditions of international students.
Nepalese student Omnharayan Sharma, studying accounting in Sydney, alleged a supervisor forced him and six others, working for B.I.C Services at 420 George Street, to pay him $100 a fortnight in cash.
Mr Sharma alleged the supervisor said the money was used to pay for another cleaner to complete additional duties, but they were never hired.
"Nothing was fair in there."
A B.I.C. spokesman said Mr Sharma's allegation was investigated by management and the union, but could not be substantiated. "If the allegations were able to be substantiated B.I.C. Services would take immediate disciplinary action against any of its employees involved in such a practice," he said.
Daniel Molina, hired by a Glad Group subcontractor to work three-hour shifts for $17 an hour, said he was never able to complete his allotted work - cleaning the toilets and floor surfaces on 12 floors at 363 George Street - in just three hours.
"I never, ever finished on time and I would just get paid for three hours' work even though I worked up to ... seven hours," said Mr Molina, who is on a working holiday visa. "It was my first job in Australia, so I thought I had to do this."
After Mr Molina complained to the union, he was employed directly by Glad and now receives the award rate and his workload has been reduced.
The owners of 363 George Street, Industry Superannuation Property Trust, said its contracts with the Glad Group provide for it to meet all appropriate awards. "If Glad were found to breach our contract, then their contract is at risk" the trust's chief executive, Daryl Browning, said.
The Glad Group's chief operating officer, Ravi Shambanna, said in a statement the company took allegations "very seriously".
"If such an issue is brought to the attention of the company immediate action is taken to ensure no cleaner is disadvantaged in payments or treated with disrespect in the workplace."
Mr Shambanna said he was not aware of Mr Molina's allegations but "issues such as described are not tolerated by the company."
Thai business student Sirikun Bunchoo, 23, was told by her employer to pay the wages of the person who replaced her when she took a sick day from cleaning a TV station.
"Many cleaners are too frightened to complain because they want to keep their work," she said.
DANIEL MOLINA, 30
On Working Holiday Visa
Employer: Glad Group Pty Ltd
I never, ever finished on time and I would just get paid for three hours work even though I worked up to six or seven hours.
OMNHARAYAN SHARMA, 30
Studying: Bachelor of Professional Accounting
Employer: B.I.C Services
Nothing was fair in there.
SIRIKUN BUNCHOO, 23
Studying: Advanced Diploma in Business
Employer: A large Sydney cleaning company
Many cleaners are too frightened to complain because they want to keep their work.