A cannabis farm consisting of more than 500 plants with a street value of £300,000 has been found.
Cleveland Police said an officer discovered the farm in a property on West Road in Loftus.
Officers are trying to find the people responsible for growing the plants, a spokeswoman said.
Police have also issued a list of "tell-tale signs which often give cannabis farms away" for which members of the public "should be vigilant".
- Windows sealed and covered in a property or the curtains permanently closed
- Bright lights on 24 hours a day or at unusual times
- A property producing a lot of heat - birds often gather on the roof of a warm property in cold weather
- Frequent and varied visitors to a property, often at unusual times
- Gardening equipment being taken into a property, such as plant pots, fertiliser, fans and industrial lighting
- Big electricity bills
- A strong smell of cannabis constantly in the street