They say six bales of silage were taken from a field in St Brelade sometime after 11 pm on Sunday night.
It wouldn’t have been an easy job, each bale would have weighed close to half a tonne and the police say the culprit would have needed some sort of machinery to shift them from the field on Le Mont Des Vignes.
The big round bales of silage cost farmers between £20 and £30 each to replace.
Anyone with information is asked to contact the police on 612612 or use the confidential line on 0800 555 111.