"We own the trademark in New Zealand and spend a lot of money in marketing those trademarks. So anyone else bringing in products of similar names or similar trademarks are infringing those under New Zealand law."
Mr van Heerden said it was "normal trade practice" to protect intellectual property and it did not matter that English Bob's Emporium was only a small boutique shop.
But Mr Wren has accused Sanitarium of "bullying".
"They said it sounds too much like Weet-Bix but it's a totally different product - English people ask me to get this in," Mr Wren said.
"If they don't want Weetabix going massive then I can understand that. But I'm a boutique English shop selling English stuff. I sell one or two a week. This is corporate bullying."
He planned to continue selling Weetabix in the meantime, but would probably have to eventually comply with the order because he could not afford to fight the larger company.
Sanitarium ordered Weetabix off the shelves of the English Corner Shop in Auckland's Onehunga in 2010.
Intellectual property expert Anna Kingsbury said the trademark law aimed to protect consumers from being confused.
"If you go to a shop with imperfect recollection wanting this product and you're confronted with a product that looks similar, that's marked similarly, is there a potential that the consumer would be confused?
"We don't want consumers to be confused, we want them to buy the product they intended to buy."
But as this case involved a small British shop trying to sell imported British products, she said, "it seems kind of heavy handed to say you can't buy it".
