About £70,000 worth of historic coins disappared during a metal detecting event.
The 200 coins, which date from Victorian and Edwardian times, are valued at about £350 each and were discovered in Twinstead on Sunday.
The sovereigns are believed to have lain undiscovered for more than 90 years before the hoard was found and dug up by enthusiasts.
Police have now been called in to investigate as the coins should have been declared to the coroner.
Only two coins were handed in on Sunday.
A further 129 coins were found during searches this week.
The whole area is now believed to have been cleared of the sovereigns.
PC Andy Long, Essex Police’s heritage crime officer, said: "All the coins found on the site are protected by the Treasure Act.
“They are treasure trove and have to be declared to the county coroner.
”We would urge anyone who has taken any of the coins or knows of their whereabouts to contact me immediately.”
Call him on 0300 333 4444 extension 406103. Emails can be sent to andrew.long@essex.pnn.police.uk
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