Key Points:

A Queensland-based New Zealander will be nearly $110,000 out of pocket after admitting his part in an international spam email operation.

Lance Atkinson, who lives in Pelican Waters, Queensland, was sentenced to pay $100,000 and costs of $7666 in the High Court at Christchurch after admitting charges under the Unsolicited Electronic Messages Act 2007.

His brother, Shane Atkinson, and Ronald Smits, both of Christchurch, have denied charges.

Internal Affairs' anti-spam compliance unit, which investigated the trio, said they were part of a network which sent more than two million unsolicited emails to New Zealand computers between September 5 and December 31 last year.

The emails promoted Herbal King, Elite Herbal and Express Herbal branded pharmaceutical products.

They were marketed through a business operated by Genbucks, a company incorporated in the Indian Ocean republic of Mauritius.

Justice Christine French said the spamming operation was believed to be one of the largest in internet history.

Atkinson was potentially liable to a penalty of $200,000 but he was given a discount for co-operating with authorities, an undertaking to comply in the future and the fact that the operation began before spamming became illegal.

Internal Affairs anti-spam compliance unit manager Joe Stewart was delighted by the decision.

"This is a first under the new law and is just reward for the effort put in by our investigators and overseas agencies, particularly the Federal Trade Commission," Mr Stewart said.

Atkinson still faces court action in the United States brought by the Federal Trade Commission.