A thief stole £27,000 worth of 'one-off designer' rings from Pressley’s Jewellery shop in Chichester earlier this month, Sussex Police has revealed.
Police want anyone with any information to come forward after the overnight break-in at the North Street store on January 7/8.
A police spokesman said: "A side window was smashed and the thief reached through to steal 14 rings from an internal shelf.
"The missing items are believed to be one-off designer pieces and have a combined value of £27,000."
Pressley's sales director Gemma Clive said the window was smashed in a 'blind spot', so wasn't 'caught by CCTV'.
She added: "The break-in was between 3 and 4am.
"It was the only blind spot in the shop and they didn't actually get inside, so the alarms didn't go off.
"We have lost nearly £30,000 worth of engagement rings."
Investigating police constable Robynn Gordon urged anyone who saw any 'suspicious activity, people or vehicles' in North Street over this period, to come forward.
She added: "We’d also urge dealers and other jewellers to be aware of this theft and to let us know immediately if they are offered such items for sale in suspicious circumstances."
Police asked anyone with any information to contact Sussex Police online or by calling 101, quoting serial 148 of 08/01.
"Alternatively they can contact Crimestoppers or call the independent charity on 0800 555 111 anonymously," the spokesman added.