A "significant" cannabis farm was found by officers after they investigated reports of a burglary.
Around 100 cannabis plants were found at a property in Rock Ferry by police through the night.
Officers were called to reports of a burglary at about 3.35am on Old Chester Road.
The force said two men were seen trying to break in to the front door of a shop, while two other men were also seen running away from the building.
As police attended, a white Ford Transit Van containing plants was outside.
After searching the property and around, 100 more were found.
Officers remained at the scene on Friday, after Scottish Power attended to make it safe.
Community inspector Tom Welch said: "This is another significant cannabis farm which had the potential to cause significant harm in our communities.
"The fact it has been found means these plants will not now be used to line the pockets of criminals who bring only misery to our streets.
"Keep reporting any suspicious behaviour, smells, sights or visitors in your area and we will take action like this
If you have any information about suspected drug production in your area, please contact @MerPolCC, 101 or Crimestoppers anonymously on 0800 555 111.
