Cannabis with a street value of almost £30,000 has been prevented from making its way onto north Kent’s streets.

A crop of more than 500 of the drug plants – almost ready to be put on the market – were found in a morning raid on a semi-detached house in Greenhithe.

The cannabis "farmer", 43-year-old Thong Dinh Vuong, was arrested at the property, in Hasted Close, last Wednesday.

He admitted cultivating cannabis at Dartford Magistrates’ Court the following day and will be sentenced at crown court later.

The plants were found growing in every room of the house apart from a small kitchen and a complicated light, heat and irrigation system had been set up, with the electricity meter bypassed.

It comes as a big increase in the number of cannabis "factories" discovered by police across the UK was revealed, which the Home Office called an "encouraging sign".

PC Adrian Parsons, north Kent’s drugs and licensing officer, said: "The outlay for an operation like this would have been around £10,000 and the plants would have had a street value of around £30,000, so someone has spent a lot of money for no return and we have removed the drugs from the market."

Anyone who spots signs of possible cannabis factories is asked to phone PC Parsons on 01474 366 346 or Kent Crimestoppers, anonymously, on 0800 555 111.