A judge in New Zealand has ordered the destruction of more than 100 boxes of British Weetabix held by customs and told a speciality grocery store it must cover the labels on any of the boxes of cereal it sells in future.

The decision follows a legal battle between A Little Bit of Britain in Christchurch and the New Zealand breakfast firm Sanitarium, which brought the case arguing that shoppers could confuse the British cereal with its trademarked product Weet-Bix.

In a reserved decision on Tuesday, Justice Gendall found there was no chance of customers being confused because Weetabix was only available at a speciality store selling British products. However, the judge ruled that A Little Bit of Britain had breached the Trade Marks Act by not covering up the label on the boxes and that the impounded Weetabix must be destroyed.

A pallet holding 108 boxes of the cereal arrived last year in a container of British goods destined for the shelves of the South Island store, which largely serves British immigrants. The boxes were seized by customs after Sanitarium complained about trademark infringement.

That decision drew scorn from British immigrants and New Zealanders alike, some of whom said they would start boycotting Sanitarium’s products in New Zealand. The hashtag #freetheweetabix was also widely shared among supporters.

Lisa Wilson, the co-owner of A Little Bit of Britain, accused Sanitarium of bullying her small, family-run business.

“They are trying to force us to do what they want because they are a multimillion-dollar company.”

Other British goods stores in the North Island have complied with Sanitarium’s demands to cover the Weetabix label when they sell the product.

Wilson said her store sold about seven boxes of Weetabix a day to mostly British nationals. She said the look, taste and packaging of Weet-Bix and Weetabix were completely different and could not be easily confused.