Police believe they uncovered one of the most sophisticated cannabis factories in Oxford yesterday.

Officers found five rooms filled with about 450 mature cannabis plants after smashing their way through the front door of the house, in Derwent Avenue, Marston, at about 9am.

Inside the terraced, three-bedroom home, they found hydroponic lights rigged to walls and ceilings in every room apart from the living room. The plants were ready to be harvested and estimated to have a street value of £90,000.

Police believe the home's electricity meter had been bypassed to power the lights without running up expensive bills. Southern Electric was also called to the house to take apart a system diverting electricity from other properties.

Sgt Yak Teladia, who led the operation, said: "This was a complex and sophisticated set up with the potential to produce cannabis worth tens of thousands of pounds.

"It seems someone would have been living inside the property who acted as a full time gardener. They were mature plants and ready to be harvested.

"There was quite an extensive hydroponics set up which was very complicated. The amount of equipment involved in this farm showed it was quite sophisticated.

"This is one of the most extensive ones I have seen."

A 77-year-old woman, who lives in Derwent Avenue, said very few people had been seen using the house.

"You hear about other places around the city but you don't hear about it on your doorstep. You might see drugs every day elsewhere but we never have any trouble down here."

An 83-year-old woman said: "I didn't know anything was wrong until I heard some shouting this morning and looked out of the window to see all the police. We're all very shocked."

A 45-year-old man said: "I didn't even think anyone lived there until recently when I saw a light on in the living room.

"When it snowed last week it was the only house where the snow melted. I thought that was strange."

Anyone with information should call police on 08458 505505.

A 24-year-old man was arrested on suspicion of possession of a controlled drug.