Four thieves used a drain cover to smash their way into a jewellery shop and steal thousands of pounds worth of stock.
At around 2.45am on Thursday, February 4, the four offenders broke into the Pandora store in Riverside Shopping Centre, Hemel Hempstead.
A large amount of jewellery was stolen before the offenders got into a dark-coloured Volkswagen Golf parked nearby.
The vehicle then sped off in the direction of the A41.
The suspects are all men and had their faces covered.
They were all wearing gloves and dark clothing, except for one who was wearing grey jogging bottoms and a thin black jacket.
Detective Constable Paula Mowbray, from the Dacorum Local Crime Unit, said: “I am appealing for anyone who may know the whereabouts of these items or who has been offered them for sale, to please get in contact.
“I would also like to hear from anyone with any other information about the incident.
“Did you see anyone acting suspiciously around the time stated? Did you see the vehicle in the area?
“Any information, no matter how seemingly insignificant, could greatly assist the investigation.”
Anyone with information should call DC Mowbray on 101, quoting crime reference D1/16/871.