An Auckland family were tucking into a bag of their favourite Bluebird chips, when they said they made a dangerous discovery.

Feeling something strange in his mouth, Eldhose Varghse spat the chips out, and said he saw the culprit: a piece of twisted metal wire embedded in between two chips.

"I was really surprised, but was most concerned for my 3-year-old son, who was eating from the same packet."

Varghse made his son spit all of the chips in his mouth out too, but said they found no more metal.

"Luckily he hadn't bitten into or swallowed any metal. If something went wrong, and he had swallowed that chip, I just can't imagine that."

Varghse said his wife and son were about halfway through the bag of Delisio fine sea salt flavoured chips on Saturday evening when they made the discovery.

They had purchased the packet at an Auckland supermarket, he said.

The piece of metal wire found inside two chips stuck together. Photo / supplied

On Sunday, Varghse said he called Bluebird, who sent him an empty return courier bag to send the half-empty packet and metal to them to investigate.

Accompanying the packet was a letter, thanking Varghse for making them aware of the incident, explaining Bluebird's manufacturing process and saying there would be an investigation.

In the fourth paragraph it reads: "Please accept our sincere apologies for any inconvenience."

Varghse said he found the letter insincere, but at that point he was not too upset.

"I thought, these things do happen in big manufacturing processes."

But then he saw the attached $20 Bluebird voucher.

"I just thought how rude. They didn't even consider the life-threatening situation of my toddler.

"I was just so worried, my family were eating those chips too. When I saw that voucher for $20, it was like they were making fun of us.

"We risk our lives eating their chips, and then they give us a voucher to go out and by the same chips."

Varghse said his complaint had nothing to do with money.

"It is about how they understand my problem. I would give the voucher back. They should have apologised sincerely, and not sent that voucher."

He said he was wary about eating chips again.

"We used to buy those chips each week when shopping, that was our favourite. Now I am a bit scared of Bluebird.

"I want to make other kids and their parents aware about such dangers."

A spokeswoman for PepsiCo, which owns Bluebird, said they were in contact with Varghse and were investigating the incident.

"We take food safety very seriously and have a number of processes in place to help ensure quality. 

"Complaints of this nature are incredibly rare."