Drugs gang turned secluded mansion into massive cannabis factory

But Mark Gallagher, aged 49, of Wolverhampton Road East, Parkfields, Wolverhampton was caught following a raid on his flat, Carlisle Crown Court heard.

Officers found 163 cannabis plants being grown and a laptop with searches for Grade II listed Flass House, in Cumbria, along with news stories on police investigations into cannabis production.

At Flass House, near Penrith, plants were found with an estimated street value between £31,700 and £63,400.

A police expert estimated that during 13 months up to May 2012, 263kg of cannabis could have been grown inside the mansion – which could have had a street value of between £2.6m and £5.26m.

Gallagher admitted conspiracy to supply cannabis bush as well as offering to supply, and possessing with intent to supply cannabis bush; the abstraction of electricity to facilitate the growing of the cannabis; and importation of more than 1,000 diazepam tablets which were shipped from abroad.

He was sentenced to four years for the Flass conspiracy, and three years for other drugs offences at Carlisle Crown Court on Tuesday by Judge Paul Batty QC.

Officers carried out a raid at his Wolverhampton flat on June 26 last year.

Tim Evans, prosecuting, said: "In the basement the police found evidence of a significant cannabis cultivation operation. Some 163 cannabis plants were being grown and they were in various stages of maturity. The equipment in the flat included 13 heat lights, 13 power transformers, five ventilation fans and one filter."

The plants found at the site near Penrith had an estimated street value of between £31,700 and £63,400.

A laptop seized from that address was analysed and showed internet searches for Flass, news stories about police investigations into cannabis production. In addition there had been a Facebook name search for one of his Flass co-conspirators.

Nicholas Rooke, defending, said financial problems led him to become involved in the plot.

"He was aware of what was going on. He knew himself what was going on was not correct," said Mr. Rooke.

Gallagher 'foolishly' set up his own cannabis farm after returning to Wolverhampton from Cumbria.

However, he did not sell the drugs that were grown.

"He certainly is extremely remorseful," said Mr Rooke.

Dean Cameron, 53, of London, was jailed for eight years, Charles Neophytou, 47, also from London, five and a half years; Philip Branigan, 32, of Surrey, seven years, David Lawrence, 32, of Ilford, eight years and Paul Davies, 64, of Southport, three years and eight months.

Judge Batty said: "You defendants were all involved in a conspiracy to produce cannabis on an industrial scale. You selected this property carefully and with precision with this criminal enterprise in mind.

"Given the scale of this operation, that it had the real hallmarks of organised crime - a gang coming from London, selecting a suitable building in a rural location in Cumbria - I regret to say that a deterrent sentence is unavoidable."