A surprise Fair Work visit to the Melbourne Cricket Ground has led to a cleaning company being fined more than $130,000 for underpaying overseas workers.

The 11 cleaners were underpaid by $37,471 for work at the MCG following AFL matches in 2014, the Fair Work Ombudsman said on Tuesday.

ISS Facility Services Australia Limited - the Australian arm of ISS Group - was fined $132,217 in the Federal Circuit Court earlier in May despite not directly employing the workers.

The cleaners were employed by the now-defunct First Group of Companies Pty Ltd, which was subcontracted by ISS, but Fair Work used accessorial liability laws to hold the latter company accountable.

The cleaners were paid flat rates of between $18 and $25 an hour, which came to light following a Fair Work visit to the MCG after the September 2014 preliminary final between Hawthorn and Port Adelaide.

Inspectors spoke to 44 cleaners, who "inundated inspectors with their desire to tell their stories," the ombudsman said.

The former owner-operators of First Group of Companies, Sharad Patel and Sidarth Luthra, were each fined $17,926 for their involvement in sham contracting.

The court was told one example of a worker having to borrow money from friends for basic living expenses including rent and bills after waiting 45 days for his first payment.

Fair Work said ISS admitted in court it knew the rates it paid First Group of Companies were "not sufficient to cover the employees' entitlements" and that the latter's payments to workers were unlawful.

But the ombudsman added ISS had since worked to improve oversight and management of its supply chain, including auditing subcontractors to see if they complied with workplace laws.