NOT HAPPY: Emma Fairbairn wants an apology from Massey Countdown after buying a tobacco pouch filled with a piece of bread.

A practical joke or a serious mistake?

Whoever the culprit was Emma Fairbairn doesn't like her daughter being the butt of it.

Jessica, 22, visited Countdown in the Auckland suburb of Massey on April 29 to buy a 30g pouch of Port Royal for $35.90.

The pouch was sealed in cellophane as per usual and Miss Fairbairn didn't notice anything awry.

But after returning to her mother's home less than an hour later she opened it and was aghast to find not only was the tobacco missing but it had also been replaced with one slice of multi-grain bread.

"It looked like Molenberg," Mrs Fairbairn said. "It was folded in half, still fresh without any mould or anything. It was totally bizarre."

Mrs Fairbairn returned to the supermarket to show the manager the unusual package, expecting a refund or replacement.

To her shock, she received neither.

"He took about 15 minutes and came back to say they wouldn't replace it because it was a security issue."

Mrs Fairbairn is a regular at the supermarket and a staff member told her it wasn't the first time bread had been found in a tobacco pouch, she said.

A spokesperson for Countdown said they took customer complaints seriously and an investigation would be carried out but that it was unlikely the product had been tampered with.

"Tobacco is stored in a secure location and is imported in a sealed pouch which is cellophane wrapped when sold.

"It would therefore be unusual to find a piece of fresh bread in a tobacco pouch, so it's not unreasonable that we would investigate what's happened.

"We apologise if the customer felt unhappy when she returned the product as this certainly wasn't our intention and we'll be investigating her complaint as quickly as we can."

The spokesperson also confirmed a similar complaint was being investigated.

A practical joke is not a good way to deter smoking, Action on Smoking and Health director Ben Youdan said.

"It's totally unique to my mind, I've never heard of anything like it in 12 years working in this field," he said.

"I probably wouldn't encourage pranking smokers, or trying to smoke sandwiches, although smoking a sandwich would probably be the most likely way to deter smoking," Mr Youdan said.

Port Royal had gone out of its way to apologise for the error, Mrs Fairbairn said.

A representative hand-delivered a fresh pouch of tobacco to their door on Wednesday along with an apology and the assurance of a full investigation into the matter.