A gang of fraudsters, operating in Bradford, have escaped with thousands of pounds after conning victims into buying fake gems and gold.
Police are now warning people not to fall victim to the con artists.
Officers are linking two recent incidents where fake gems and gold were used to encourage people to hand over their money.
The latest con happened on Wednesday, when a man was approached in the centre of Bradford and offered a quantity of gems for sale.
He was given a sample of the “jewels” by two men and then taken to a woman who verified the price of the stones and agreed to buy them at a higher price than the victim had been told they were worth.
PC Toni Hinnells said: “Believing he was going to benefit, he handed over £10,000 in savings to secure the sale.
“After being handed the gems, the victim discovered that they were fake and worthless. Those involved could not be traced or contacted.”
Police have released CCTV images of two men they want to speak to in connection with the offence.
A similar incident took place on February 25, when a delivery driver was contacted about a job transporting items between Manchester and Huddersfield.
PC Hinnells said: “He met with a man in Bradford city centre for payment, who then took him to see his manager. Two gold bars were produced which they claimed were to be sold in order to pay for the delivery.
“After the gold was valued by a third man, the victim agreed to pay a deposit of £2,000 so it could be taken elsewhere for sale. Once the money had been handed over all the men involved disappeared with the gold and the cash.”
Anyone who has information about the incidents can contact PC Hinnells, or PC Gudgeon, of Bradford South Police, on the non-emergency number 101, or Crimestoppers in confidence on 0800 555 111.