The $100 note was found at a Tamworth business, with the Oxley Police District urging business owners to check the authenticity of notes being passed.

One business reported coming across two within 24 hours.

Plastic: Australian banknotes are printed on plastic and have a distinct feel. A suspect banknote may feel excessively thick or thin compared to a genuine banknote. It is difficult to start a tear along the edge of a genuine banknote. You can also try scrunching the banknote in your hand – a genuine banknote should spring back.

A coat of Arms

Look for the star:  Diamond-shaped patterns are printed inside a circle on both sides of the banknote. If you hold the banknote up to the light, the patterns should line up perfectly to form a seven-pointed star.

The clear window: Check that the white image printed on the window cannot be easily rubbed off. Also look for the embossing – there is a wave pattern in the window of the $10 banknote, and the value of the banknote in the windows of $20, $50 and $100 banknotes.

If you come across a banknote that you suspect is counterfeit report the matter immediately to State or Federal police.