POLICE were tipped off about a cannabis farm in Halliwell — after the growers left the front door open.

A pedestrian in Harold Street was surprised to spy the plants through the open door of the house.

He rang police just before 11pm on February 25, and they found approximately 100 plants, carrying a total street value of £50,000 being grown inside when they arrived the next morning.

Before the police came, the caller, who lived nearby, heard some banging from the house and saw two men running away across Harold Street.

On Thursday morning, neighbourhood officers attended and removed all plants and hydroponics equipment, with the plants taken away for forensic analysis before they were destroyed.

When police arrived, they saw the front door of the house had been damaged and was open.

Electricians were called to the house and found that the meter had not been bypassed, as is often the case with cannabis farms.

The house was secured, with the front door boarded up.

Police have not made any arrests so far and are appealing for people who know the identity of the farmers to come forward.

Sgt Jon Seeds said: "The cannabis farm was discovered as the result of information provided by a member of the public.

"This resulted in a sizeable commercial cannabis farm being dismantled and has assisted the neighbourhood policing team in disruption of the criminal activity within the area.

"Residents are asked to keep an eye out for tell tale signs such as pungent smells emanating from or near an address and different occupants that may visit at all times of the day or night."

About 100 plants were found at the house, with a plant typically carrying a street value of between £400 and £500.

They are cropped every 12 weeks, meaning they could have yielded between £160,000 and £200,000 for the growers over the course of a year.

Last year, police across Greater Manchester sent out “scratch and sniff” cards to 10,000 homes so members of the public could recognise the smell of the illegal plant.

The cards emitted the sickly sweet smell of cannabis, which the plant emits as it is growing.

The leaflets also warned residents to look out for high-tech equipment, covered or blocked windows, lighting and buzzing ventilation.

Anyone with information on the Harold Street farm, or anyone who suspects someone living near them is growing the drug, should call police on 101 or Crimestoppers, anonymously, on 0800 555 111.