Five millstones worth hundreds of pounds each have been stolen from the historic Jill windmill, just north of Brighton.
The stones weigh around half a tonne each and it's believed they were taken sometime in the last week.
It's thought it would have taken four to six people to manhandle them off the site in Clayton, possibly in the daytime as doing so in the dark could have proved too dangerous.
The 19th century corn windmill sits atop the South Downs with nearby Jack.
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Amanda Houston has Thursday's weather forecast for the east of the Meridian region.
Amanda Houston has today's forecast for the west of the Meridian region.
Amanda Houston has the latest weather forecast for the west of the Meridian region.