Police are appealing for information after four yellow Thwaites dumper trucks were stolen from a locked compound in Lincoln.
Sometime between noon on March 14, and before 9am on March 16, offenders cut the fence to the T C Harrison JCB Limited compound on Whisby Way.
They then drove away in the trucks through the gap.
Police officers have visited the business and checked the CCTV. The investigation is still ongoing.
Anyone who saw anything suspicous should contact Lincolnshire Police on 101 quoting incident number 61 of March 16.