More than £100,000 has been stolen from a "secure storage area" at the former headquarters of Warwickshire Police.
The force said £113,000 which was seized from criminals had disappeared from a 'designated site' at its former base in the village of Leek Wooton.
It was first reported missing in September last year sparking a confidential internal investigation by the force's Anti Corruption unit.
There are currently no indications of who may have taken the money.
The matter has now been formally passed on to the Independent Police Complaints Commission (IPCC), which has decided that it should be investigated locally.
The police are now issuing a public appeal to trace anyone with information about the missing cash.