Members of the public are being asked to stay alert to strangers selling high-value electronic equipment in the street.
Kent Police is investigating two incidents where members of the public have been approached by men offering to sell computer equipment and smart phones for cash.
However, in both incidents, the unsuspecting buyers have not come away with what they thought they had paid for.
On Monday 10 March a man in his 30s was walking along Pencester Road, Dover, when he was approached by a man asking if he wanted to buy an iPhone and laptop.
The pair then walked towards the Charlton Shopping Centre and entered a nearby car park where the stranger showed the man the laptop in a dark-coloured van. They agreed a price and the stranger put the items in a backpack.
As the pair walked away, the seller put the backpack on the back of the victim before they headed to a nearby bank and money was exchanged. They then went their separate ways but when the buyer checked the contents of the backpack he found it contained cardboard and a pack of potatoes.
The following day, on Tuesday 11 March, another member of the public was approached by a man offering to sell a phone and tablet at the rear of the Mecca Bingo hall in Ashford. He showed the man and his friend the electronic equipment, agreed a price and told them to meet him in the car park of Asda in Kimberley Way.
The victim and his friend went to the car park later that day where the man showed them the rucksack containing the phone and tablet again. Cash was handed over to the seller who put it in his car before coming back and handing over the bag.
But as the man and his friend returned to their vehicle they discovered the bag did not contain the phone or tablet, but several pieces of cardboard and three bottles of fizzy drink.
The offender left the scene before they could challenge him.
Officers are investigating both incidents and are pursuing a number of lines of enquiry but are urging members of the public to stay alert to the dangers of buying products on the street.
They would also like to hear from anyone who may have been approached in recent weeks in similar circumstances.
