A Golden Bay fisherman whose wife became violently ill after eating a takeaway gluten-free pizza, took revenge on the shop by dumping 100 fish carcasses outside the shop.

Police prosecutor Sergeant Graeme Eden said Leigh Kelly admitted dumping the fish outside the takeaway business attached to the Pohara Store because he was angry at having paid more for a gluten-free pizza and he believed it was not gluten free after his wife got ill.

Mr Eden said Kelly owned a fishing charter business and over the weekend of March 18 was involved in organising a fishing club's visit to Golden Bay to go fishing.

He said on the Sunday night Kelly had been drinking at home and drove to Pohara General Store and emptied a large chilly bin on to the picnic table and waiting area at the front of the shop.

The chilly bin contained fish frames and off-cuts from fish caught by the club over the weekend.

Mr Eden said Kelly drove away and returned at 4.15am dumping another load of rotting fish in the same area.

Three distinct piles of fish were dumped outside the shop totalling more than 100 fish frames, he said.

Defence lawyer Rob Ord said Kelly accepted he was guilty and had over-reacted.

In the Nelson District Court yesterday, Kelly pleaded guilty to a charge of disorderly behaviour.

Judge David McKegg fined Kelly $500 and ordered him to pay $353 in an emotional harm repayment.

Judge McKegg said Kelly had acted childishly against someone's livelihood and left a disgusting mess to deal with and it did have an effect on them.

Today, Pohara store owner Shona Martin said she had been making gluten-free products for more than 10 years as her husband, Russell, had coeliac disease.

All the staff were trained in gluten-free products and "sensitive to customer requirements".

The store, which was bought by the couple about 18 months ago, sold many gluten-free products. Mrs Kelly's pizza was made by the head chef who was "100 per cent sure" it was gluten free.