The owners of a Gloria Jeans cafe in Melbourne have been fined $110,500 for underpaying staff.

The owners of a Gloria Jeans cafe franchise in Melbourne have been fined $110,500 for underpaying staff for almost two years.

They also have to back pay $83,566 to 22 underpaid staff, many of them international students.

Inspectors from the Fair Work Ombudsman found the casual staff were paid flat hourly rates of $8 - $10, and workplace laws on providing meal breaks and payslips were also breached.

The owners of the Caulfield franchise - Tsinman Fu of Clayton and Ping Ostrovskih of Rowville - were fined $17,500 and $13,000 respectively.

Their business was also fined $80,000, when the case came before the Federal Circuit Court.

The judge said a "conscious decision was made to reduce wages when the business was not producing sufficient income" and the owners were "well aware of their obligations and the seriousness of those obligations".

The underpayment occurred from mid 2011 to early 2013.