UPDATED 2.25pm: The Green Party are saying stricter controls are needed on fisheries imports.
It's emerged New Zealand's imported more than 600 tonnes of seafood from an outfit in Thailand that's known for using slave labour.
The company has been condemned for locking labourers in cages, and not paying wages.
Greens Primary Industries spokeswoman Eugenie Sage said import controls should be tighter.
"I think government needs to be looking at other legislation to ensure that we are not having products from indentured labour sold in New Zealand."
We have import control regulations on products produced in prison, and the Green Party argues the same should apply for products made in slavery.
Sage said supermarkets need to look at what they're selling "so that they can provide robust assurances that they are selling products that come from ethical fishing practices and ethical work practices."
The seafood giant Thai Union sells shrimp, fish fillets, canned tuna and salmon, and material used for pet food.
Slavery is widespread in the Thai fishing industry, with some workers kept in cages between fishing trips, and others working 16-hour shifts without pay.
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