The state government recovered almost $1.2 million in unpaid worker entitlements last financial year.
The Department of Commerce and Labour Relations Division found many of the underpayments during 493 investigations into employee complaints that they had not been paid correctly.
The underpayments were as little as a few hundred dollars and as large as $30,000.
Commerce Minister Bill Marmion said the Act set minimum employee entitlements across all industries.
"Any breach of such minimum entitlements is of great concern," Mr Marmion said.
"Overwhelmingly, we find that a lack of understanding is the major contributing factor to employers underpaying their staff. However, unfortunately we do find that some employers deliberately underpay their staff," he said.
The department also finalised prosecutions against seven employers for breaching employment laws, which led to the recovery of a further $47,000 in underpayments.
In March 2010, the Industrial Magistrates Court fined a trolley collecting service $1,950 for underpaying two employees and ordered back pay totalling $5,062.
In another matter, the Industrial Magistrate's Court ordered an accounting firm to back pay an employee $7,113 for failing to pay a long service leave entitlement.
