A HUGE cannabis farm worth up to £1 million over the course of a year has been discovered by police.

Police raided the terraced house in Tildsley Street, Great Lever, at 8am today.

They found nearly 500 plants on the second floor and in the loft.

Police say the electricity supply had been bypassed in such a way that there was a risk of an "explosion".

Engineers have had to dig up the pavement today to repair the damage caused to the street's electricity cabling.

A man has been arrested on suspicion of cultivating cannabis and has been taken into police custody to be quizzed.

The plants are worth between £400 and £500 each.

Officers found 488 plants at the house, which are together worth somewhere between £195,000 and £245,000.

They are cropped every 12 weeks, meaning they could have yielded between £800,000 and £1 million for the growers in the next 12 months.

PC Graeme Sharp said: “Whatever your view on cannabis, this factory was incredibly dangerous due to the bypassing of the electric metre.

“The growers were putting both themselves and their neighbours at risk of fire or explosion and it has taken a visit from the electric board to make it safe.

“In fact, such was the damage caused to the electricity set-up on the street, they needed to send a digger to rip up the pavement, causing considerable cost and disruption to the people who live there."

Police had been tipped off that a farm was operating at the house and forced entry into the property.

Inside they found the plants and a man, who they arrested on suspicion of growing cannabis.

The farm was bypassing the electricity meter, with the lights needed to grow the cannabis taking power from the street’s main supply.

The plants have been bagged up by police and destroyed.

In September, a similar-sized farm was found in a disused nightclub building in Bolton town centre.

Police raided Club Ice and The Late Club on September 19, finding between 450 and 500 plants.

Nobody was in the clubs and the growers have not been caught.

Earlier this 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 cannabis farms can ring police on 101 or Crimestoppers, anonymously, on 0800 555111.