A police force is offering an amnesty to people who fiddle their mobile phone insurance to get an upgrade.
Many of the sought after latest mobile phones can take pictures
South Yorkshire Police have set up a free phone number for people to report false mobile phone thefts.
There are 160 false reports a month which cost £1m per year to investigate.
Those involved in the claims are either owners wanting to get a newer phone or shop staff encouraging customers to make a false claim so they can earn commission.
Detective Suprintendent Paul Broadbent said: "At the moment we've got a number, albeit a small number, of shop assistants who we believe are encouraging people to commit a crime or to take part in a crime.
"Those (are) shop assistants who are on commission and only out to make a fast buck.
"And there are also a number of people who have been out the night before who have lost their mobile phones.
"They make a false report that they have been assaulted or robbed in order to get a crime number - that valuable crime number - so they can make a claim on the insurance.
"People don't see it as a criminal offence. They see it as fiddling their insurance."
South Yorkshire Police say that while investigations are being conducted into a non-existent crime, officers could be working on genuine criminal cases.
The free phone number is 0500 510999 runs from Monday 15 March until 15 April.
Letters have been sent to retailers about the illegal practice, warning they will be prosecuted if caught after the amnesty.
Detective Chief Inspector Chris Foster of the National Mobile Phone Crime Unit said they had discovered occasions when shop staff encourage false reports.
"Whether they do it for a favour or because they are on commission....really clouds the issue for us.
"We believe that when a mobile phone is reported stolen, on 15%-20% of occasions that is false."