The latest case of worker exploitation on Marlborough vineyards signals a concerning level of exploitation of workers in Aotearoa, the Maori Party says.

"Some people will most likely never look at wine from vineyards in Marlborough quite the same now after finding out that some workers there were purposely paid under the minimum wage and as low as $2 an hour," Maori Party MP for Te Tai Tonga, which includes the South Island, Rahui Katene said.

The Employment Relations Authority ruled that New Zealand Vines Limited underpaid several workers, mainly immigrants, it employed to work in the vineyards.

"The Maori Party supports the right for employees to be treated fairly and with dignity and we encourage the Labour Department to talk with the Economic Development Ministry about how they can prevent this company and its director from reoffending."

While the owners of the vineyards did not have a direct contract with the workers, they too had a responsibility to report exploitation, especially if the abuse was taking part on their property, Mrs Katene said.

"Vineyard owners must not turn a blind eye, they too must speak up."

Besides pushing for the minimum wage to be raised to $15 an hour, the Maori Party also plans to seek amendments to Employment Relations Act to make it worker-friendly.