The operators of Mamak Malaysian restaurant in Haymarket have been fined almost $300,000 for paying workers as little as $11 an hour.

Federal Circuit Court Judge Justin Smith found the Goulburn Street restaurant had deliberately ignored its workplace obligations "to maximise profit".

The operators of Mamak have been fined almost $300,000 for under-paying staff. Credit:Jennifer Soo

The Fair Work Ombudsman took legal action against the popular inner Sydney restaurant which relied on informal market research to set wages.

An Ombudsman investigation found six employees, including five visa holders from non-English speaking backgrounds, were collectively underpaid more than $87,000. They were paid as little as $11 an hour between February 2012 and April 2015.