Two men used a simple switch to steal a €175,000 diamond from the Gassan Diamonds showroom in Amsterdam, police said.

The two managed to swap the real gem for a fake made of zircon while looking at the stones earlier this month.

Gassan spokesman Benno Leeser said the men had planned the theft very professionally and had visited the shop the day before to check out which zircon they needed to bring to make the swap.

‘One chatted to staff to distract them while the other made the switch,’ Leeser told the Parool.

Police have now distributed security camera footage of the two in the hope someone recognises them. The men, both of Asian appearance, spoke English and Chinese and may be staying in a city hotel, police said.

According to the Parool, Gassan Diamonds has since suspended a member of staff.