The wine industry says rogue operators paying workers as little as $2 an hour are the exception rather than the rule.

A company in Blenheim, New Zealand Vines Limited, has lost a case brought against it by the Department of Labour for underpaying at least six workers.

Wine Marlborough executive officer Gerald Hope says such underpayment is not something they have a big problem with in Marlborough. He says several years ago they had a propensity for fly-by-night contractors and there were issues with non-payment, or below rate payments. But he says in general, it is not a common occurrence now.

Mr Hope says although he supports compulsory registration, he thinks forcing people would be a bit heavy-handed.