Three men have been arrested after several hundred cannabis plants were found at house where a burglary was taking place.
Police were called to Park Street South in Blakenhall, Wolverhampton, at about 0500 BST following reports a burglary was going on.
When officers searched the property, they discovered that the house was being used as a cannabis factory.
About 300 plants were found, a police spokesman said.
Three men were arrested at the scene and are currently helping police with their inquiries.
Specialist forensic officers will examine the scene later.