Nearly one in every five Australians steal from supermarkets by engaging in dishonest behavior at self-service checkouts, according to a recent survey.

In new research, 9% of shoppers admitted to not scanning items before leaving the supermarket, while another 10% deliberately lied about what they had scanned to get a cheaper price - for example, putting avocado on the scales but saying it was an onion.

That is according to a nationally representative survey of 1010 respondents conducted by Finder.

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Extrapolating throughout the country, it would mean that 3.8 million Australians stole in the last year. "Of course, most self-checkout machines can't tell brown onions from portobello mushrooms," he said.

"I suspect a lot of Australians don't regard scanning items incorrectly on purpose to be the same level of theft as running out of a shop with a loaf of bread."

According to the data, 2% of Australians have dined and dashed in the last year. 6% said they had driven away without paying for petrol. If you haven't stolen anything in the past year, you are among 81% of Australians.

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