Ceremonial chains worn by the Lord Mayor of Bristol remain missing eight months after they were stolen in a raid on a council building.
The 18 and 23-carat jewellery was in one of two safes dragged out of the property by a van in Hotwell.
Three people arrested in August in connection with the theft have been released under investigation.
Avon and Somerset Police believe the chains might still be in the area and have renewed an appeal for information.
The two pieces of jewellery, worn by the Lord Mayor and Lady Mayoress, were stolen from an authority building on Smeaton Road in the early hours of 24 February.
One safe was found by a member of the public the following day in Greville Smyth Park, and the other, which had contained the chains, was found dumped in Greatstone Lane, Winford.
Investigating officer Beth Sutor said: "We don't believe the chains were specifically targeted, more that this was an opportunistic crime.
"There is reason to believe that the chains may still be in the Winford or Chew Valley area."
Detectives said they had used CCTV footage to trace the route of the van as it left the city and established six people were involved.