How an ordinary chicken sandwich ended up costing granny more than $3k in Brisbane after simple mistake

A forgotten sandwich in a backpack has turned into a costly nightmare for an elderly  pensioner.

June Armstrong, 77, from New Zealand, bought a muffin and a gluten-free chicken and lettuce sandwich at Christchurch Airport before an early morning flight to Brisbane in May.

She ate the muffin and put the sealed sandwich in her backpack to eat during the three-and-a-half-hour flight.

Ms Armstrong fell asleep during the flight and completely forgot about the uneaten meal stashed in her bag.

Then when she filled out the customs declaration form, she forgot to declare it.

It wasn't until she was confronted by Australian Border Force officials who went through her backpack upon arrival that she realised her expensive mistake.

She burst into tears at the airport after being slapped with a massive fine.

'I was just sobbing and said '$3,300 for a little sandwich?' she told the New Zealand Herald.

Mrs Armstrong tried to appeal the fine within the 28-day payment period but after a series of automatic responses, ended up paying it to meet the deadline.

'My husband kept saying, "Just pay it". I said, "It's our pension, we can't afford this".'

Six months on, Ms Armstrong is still contesting the fine which has taken a physical and mental toll on her.

'I think of it night and day, I now am on sleeping tablets,' she wrote in her submission to the Australian Department of Agriculture, Fisheries and Forestry.

'I am consumed by how much this fine was and how much it will affect our lives.'

Ms Armstrong still hasn't received a response from Australian authorities and has come to terms with the likely possibility that the fine won't be overturned.

But she hopes her ordeal with serve as a warning to other travellers.

'I should let it go, and my husband says I should, but they just don't give me any answers,' Ms Armstrong said.

'Everybody I show the fine to is dumbfounded, they just can't believe it.'

Travellers bringing food items into Australia need to declare them on their incoming passenger card.

'Biosecurity officers may need to inspect some of the food you're bringing with you,' the ABF website states.

While bread products can be brought into Australia for personal consumption, they must not contain meat or uncanned animal products. 

If a traveller fails to declare items known to pose a 'high level of biosecurity risk', an infringement notice can increase to 12 points (worth $3756) 'depending on the risk of the goods'.