Sky subscribers are sharing account details with friends to get behind the paywall and watch for free.
This week, the pay-to-view network admitted the practice of sharing password details for iSKY internet accounts was causing concern and it was moving to plug the gap.
Sky, which last week lost rights to broadcast Premier League English football games to a partnership between Coliseum Sports Media and TVNZ, would not disclose how many subscribers were using the iSKY service.
Head of corporate communications Kirsty Way said, "We are aware some people are using this service unfairly. We have some developments underway to help prevent this in the future. We're not quite ready to talk about them." People with a television subscription can get an iSKY log-in and pass that on, meaning one person watching on TV off a decoder, while somone else viewed via the internet at another venue.
Mike Ross' friends gave him their iSKY account details after he complained about not being able to watch sport.