More than 1,000 suspected cannabis plants were discovered inside a former cinema in Long Eaton after police were called to reports of a suspected burglary.
Officers attended the former Galaxy Cinema, on Derby Road, in the centre of the town, at around 9.30am on Saturday.
When they arrived they discovered that a suspected cannabis factory had been set up inside the derelict building, which has been empty for around six months.
More than 1,000 suspected cannabis plants were found in six different rooms, and hydroponic growing equipment was also found.
A spokesman for Derbyshire Police said that inquiries and forensic examinations are continuing at the scene. The equipment and plants have been taken away.
Anyone with any information is asked to contact Derbyshire police on the non-emergency number 101.