A mobile phone reported stolen in Croydon was returned to its owner after police managed to track it down on an internet auction site.
The victim - a 32 year-old woman - reported that her phone had been stolen in a sandwich shop in Croydon town centre on March 10.
Police officers failed to identify any suspects and the shop's CCTV had not recorded the incident.
However, police then received an alert that the phone's IMEI number had been checked by somebody using a service - called CheckMEND - that allows people to see if a phone has been reported stolen or been blocked.
Officers discovered the phone had been put up for sale and tracked the offender to Princess Road.
They found a 29-year-old woman who claimed she found the phone in the town centre and decided to sell it on.
She told the officers who the phone had been sold to so they were able to retrieve the phone from the buyer and return it to the owner on April 17.
The 29-year-old was given an adult caution for theft by finding.
PC Robert Sidney from the Broad Green safer neighbourhoods team, said: "This case highlights two important points. Firstly, if you're buying a phone second-hand or over the internet, then it is definitely worth checking to see if it has been reported stolen.
"You can do this through the CheckMEND website and whilst there is a small fee, it could save you a lot of money later on.
"Secondly, whether you find a phone or any other expensive item or gadget in the street, then you could be committing an offence by simply keeping it.
"You should contact police or attend a police station to hand it in. If it doesn't get claimed by the owner then it will be given to the finder, but if you just keep it then you could be committing a criminal offence."
You can check whether a phone has been reported stolen by using the CheckMEND service. Visit www.checkmend.com/uk for more information.
