Police have uncovered one of the largest cannabis factories in Sutton’s history, containing around 3,000 plants.

The factory was spread out over four floors of a disused office building at Sutherland House, Brighton Road, Sutton - just a few yards from Sutton train station.

The drug haul is thought to be worth somehwere in the region of £1.5m.

Police were alerted after an electrician was called to carry out some work by the building’s management company.

The electrician became suspicious and told a passing PCSO who was on patrol near the building at the time.

Officers estimate the 6th - 9th floors contained around 3,000 plants - two of the floors contained plants three feet high that were within days of being harvested.

The other floors contained a nursery, a drying room and living accommodation for two people complete with beds.

Officers forced entry to the top floors and were apparently “astounded” by what they found.

Forensics experts were called in to gather initial evidence and to take photographs while the police helicopter circled overhead in case the suspects were on the roof of the building.

Sgt Dave Williams, of Sutton South Safer Neighbourhoods Team, said: “It’s the biggest find I have ever had.”

Police confirmed that no arrests have been made but investigations are ongoing.