Another Melbourne company that sacked workers using new federal industrial laws is under inspection from the government's workplace inspectors.
It comes after a similar investigation at an abattoir in New South Wales prompted that company to withdraw termination notices to 29 sacked workers.
A Port Melbourne company, Triangle Cables, has used the same laws to fire at least eight employees who were union members.
The Office of Workplace Services is investigating, but the National Union of Workers' Tim Kennedy says the union has not been contacted.
"We've been advised that the Office of Workplace Services is investigating it, but they have not formally notified the union or been in contact with the union whatsoever.
What should happen is the workers should be reinstated without loss of service and go back to work, because there is work there for them. The company has been advertising on the internet for their positions."