He suspected the larvae must have been in the meat at the store.
"I'm not a scientist or entomologist ... but I don't think flies or maggots appear over one night. I'm disgusted that I fed that sort of food to my guests."
The test report states it would have been "extremely unlikely that the larvae would have survived both freezing and cooking of the same meat product".
But it goes on to say "the larvae received were in the third instar stage of development with an average length of 13.3mm".
"At a constant temperature of 20C it would take approximately three days for larvae to reach the same approximate length and stage as the larvae submitted".
Mr Tomlinson had been offered a refund and a $30 food voucher but felt this did not "cut it".
Foodstuffs New Zealand group general marketing manager Steve Bayliss said the company had rigorous food safety processes.
"In regards to this particular situation we have undertaken extensive independent laboratory tests, which concluded the larvae were likely to have appeared on the meat after it was bought and then cooked as this type of larvae would not have survived either a freezing or cooking process."