The High Court has ruled that internet streaming using My Box to watch SKY TV movies, television and sports programmes is a breach of copyright and illegal.
Sky TV took the action under the Fair Trading Act because it said consumers were being duped.
The pay TV operator took a case against My Box and claimed that its so-called Kodi boxes with pre-installed software were not a legal way to watch its content.
SKY TV counsel Sophie Moloney said consumers had been fooled into thinking that the boxes were a legal way to watch its content.
"Essentially these boxes have been marketed and sold as legal options for accessing sports and entertainment for a one-off fee, when all they do is find and broadcast pirate streams," Ms Moloney said.
She said Sky TV took the action under the Fair Trading Act because consumers were being duped.
"The Court's decision sends a strong message that any marketing claims that the content on these boxes can be watched legally are untrue."
A Hamilton-based man, Krish Reddy, was behind the My Box business and claimed that thousands had been sold to consumers. He was no immediately available for comment.
Ms Moloney said Sky will now seek more information about how many people may be using the boxes as part of its damages claim against My Box next year.