Supermarkets are hoping that self-service checkouts will save on costs, but the automatic machines are being outwitted by customers.

Coles, a major Australian supermarket chain, will only allow shoppers to use self-service checkouts to pay for a dozen items or less.

The initiative, currently in a trial phase, was launched in response to widespread shoplifting in its stores across the country.

Instead of paying for expensive products, shoppers have been scanning cheaper vegetables including carrots, onions or potatoes to save money.

The scam was first discovered in 2012 when “a large supermarket chain in Australia discovered that it had sold more carrots than it had, in fact, had in stock”, according to a report published in April by a criminologist from the Australian National University.

In the report, its author Emmeline Taylor coined the term swipers.

Swipers are shoppers who engage in the self-checkout scam but aren’t people who normally steal, and they do not acknowledge their actions are classified as shoplifting.

Last year, New South Wales police targeted people engaging in supermarket fraud.

Almost half of those caught shoplifting were doing so through self-service checkouts.

However, there has been no extensive crackdown on the fraudulent practice in Australia — until now.