A CANNABIS factory was discovered by firefighters called to a blaze at a house.

Around 400 plants with a street value of tens of thousands, along with a sophisticated hydroponics set-up including lamps, an irrigation system and air vents, were found at the property in Frettons, Basildon.

Fire crews from Basildon and Corringham were called to the terraced house after worried neighbours saw smoke billowing from the roof.

One neighbour, who kicked the door in believing people were trapped inside, described his shock at discovering the vast amount of drugs.

The 27-year-old dad, who did not want to be named, said: "I went over and one of my neighbours said he thought there was a woman and baby inside, so I did what every man would do and kicked the door down.

"When I went in there was a big sheet hanging from the ceiling over the stairs and when I went up the stairs the three bedrooms were stuffed with cannabis and equipment.

"It's shocking just to think that something like this is bang on your doorstep, but I suppose it could be anywhere."

The man said after the arrival of fire crews at 9am on Saturday, around 30 police officers turned up. He said they seized the plants as well as equipment, including bags of soil and 36 lamps.

The people living at the house, believed to be a Vietnamese or Chinese couple with a young baby who rented the property, were not in at the time of the blaze.

The pair, aged in their 20s, pulled up outside their home in a taxi on Sunday afternoon but made a quick exit when they realised their secret was out.

PC Simon Newman, an officer at Laindon, said the hydroponics were highly sophisticated.

He said: "They had irrigation coming from the bathroom taps which had been left running.

"They also had hydroponic lamps and silver funnels going into the roof to take the excess moisture and heat out of the room.

"They certainly knew what they were doing."

The fire is believed to have started after a home-made electrical fuse board caught alight. None of the cannabis plants were burnt.

Yesterday the house stood empty. The living room had soil strewn over the floor and, in a tiny room at the back of the house, former occupiers had left a dirty mattress scattered with clothes, a TV and a child's chair made of plastic.

Police are appealing for anyone with information about the couple's whereabouts to call them at Basildon on 01268 532212 or Crimestoppers, anonymously, on 0800 555 111.