A woman managed to trick a supermarket self-service checkout machine to recognise a $20 meat pack as 89 cents worth of onions.

Syvana Blight went to PAK'nSAVE on March 9 and printed out three tags from the fruit and vegetable barcode printer, Judge David Cameron said in the Whanganui District Court.

She continued to the meat section, placing the barcodes on the meat packs. All the tags had prices under $1 on them.

When Blight went through the self-checkout, she scanned the new barcodes for the meat packs, receiving the lot for $2.53.


She returned the next day to commit the same crime, sticking an 89 cent onion barcode on a $20 meat pack.

This time Blight was caught by a security manager, who confronted her, Judge Cameron said.

She was "verbally abusive", and when the security guard tried to hand her a trespass notice, Blight knocked it out of their hand.

The security guard bent to pick up the notice, saying the police would be getting involved.

Blight then tried to grab the trespass notice back, scratching the security guard's wrist in the process and drawing blood.

She has pleaded guilty to shoplifting and assault.

Judge Cameron said she had an "extensive history" and gave no "real" indication of remorse.

He sentenced her to four months community detention and six months of supervision. He also ordered her to pay reparation of $63.32.