A business in Northampton has been a victim of a con trick, police have warned.
The shop, in the Duston area was targeted with a scheme known by police as 'ringing the changes'.
In such scams, the fraudster will ask the person behind the counter to change notes into a different denomination, for example 10 x £20 notes changed to 20 x £10 notes.
Sleight of hand is then used by the fraudster as he openly counts the cash while secretly pocketing some of it.
All that remains is for him to make a second request that is so impractical that it will be denied (eg having £20 worth of 10 pence pieces). At that point, he demands to swap his original money back.
Sarah Whitehead, the neighbourhood policing beat manager for Northampton, said: "It results in the customer walking away with their original notes and additional money from the till that they were not entitled to."
Northamptonshire Police have now issued advice on how to avoid the 'ringing the changes' con.
* Remain calm and take your time when dealing with change.
* Decline any additional requests to change notes / coins for customers.
* If you are happy to offer change, ask a colleague to be present during the transaction.
If you would like additional crime prevention advice, please visit www.northants.police.uk