A tough penalty's been handed down to a repeat offender for exploiting migrant workers.

Auckland's Genji Ponsonby restaurant has been ordered to pay $12,000 dollars for failing to pay wages.

Labour Inspectorate's David Milne says owner William Tan has been in trouble before.

"It impacts not only on the workers directly, but on the wider community," he says.

David Milne hopes the fine is a reminder that migrant exploitation is unacceptable.