Gang members who ran a multi-million pound conspiracy to grow £25million worth of cannabis have been jailed.

The gang produced industrial amounts of cannabis at farms in Kent and Norfolk between 2013 and 2015 which made £25m a year.

Kent and Essex serious crime directorate found 16,428 plants grown by 14 members from across south east London and Kent.

The gang operated from sites in Rochester, Sittingbourne and North Walsham.

Police said sites were built in an identical fashion, two story wooden constructions built into industrial units in Rochester, Gravesend and

Norfolk.

One farm, in Canal Basin in Gravesend, was found by police after a chance find of a cannabis plant discarded near to where Police were investigating a disturbance in the early hours of Wednesday, June 17 2015.

A search by police found a farm that was set up to produce four crops a year with a street value of more than £16m.

Police found secret rooms inside a total of three different warehouses where 9,888 cannabis plants were being grown.

Police found that electricity supply to one of the units had been tampered with and the meter had been bypassed.

The estimated loss of revenue for every 30 days has been estimated in excess of £5,000.

A second warehouse was also illegally connected to a power supply causing a loss of £14,805 for every 30 days.

The site in Norfolk was producing enough cannabis to generate in excess of £3M a year and the setup in Sittingbourne was producing enough crop to make £7.5M a year at street value.

Detective Inspector James Derham, from the Kent and Essex serious crime directorate, said: "This was a highly organised and prolific conspiracy to produce and sell cannabis on an industrial scale

"We estimate the annual street value of these plants was in excess of £26 million – a significant amount of money that could have been used to fund further criminal activity.

"This case was a significant undertaking by the investigation team due to the level of sophistication and analytical work. This case sends out a clear message that Kent Police has the resources and expertise to offenders involved in high level, organised criminality to justice.

14 men were involved with the production of the cannabis and were sentenced at the Old Bailey during a four day hearing, which concluded on Thursday July 27.

One offender was James Allen, 39 and of Woolwich Road in Abbey Wood. He was sentenced to seven years. He had previously pleaded guilty to five counts of conspiring to produce cannabis and three counts of abstracting electricity.

David Graham, 51 and of Plaistow Lane in Bromley, was sentenced to nine and a half years. He had previously pleaded guilty to five counts of conspiring to produce cannabis and five counts of abstracting electricity.

Another, Alan Marquiss, will be sentenced in September for his role.

Marquiss, 69 and of Disraeli Road in Thamesmead, London, will be sentenced in September 2017.

He pleaded guilty during proceedings to one count of conspiring to produce cannabis and one count of abstracting electricity.

Other members of the gang include:

Stephen Macey, 25 and of Commercial Road in Paddock Wood, was sentenced to six years. He had previously pleaded guilty to five counts of conspiring to produce cannabis and five counts of abstracting electricity.

Christopher Marsh, 30 and of Ethelbert Road in Margate was sentenced to four years. He had previously pleaded guilty to one count of conspiring to produce cannabis and one count of abstracting electricity.

Damon Mills, 18 also of Ethelbert Road in Margate, was sentenced to 18 months. He had previously pleaded guilty to one count of conspiring to produce cannabis and one count of abstracting electricity.

Michael Edward Corcoran, 51 and of Mount Avenue in Yalding, was sentenced to 14 years. He was found guilty of seven counts of conspiring to produce cannabis and five counts of abstracting electricity.

Michael Jay Corcoran, 28 of Odo Rise in Gillingham, the son of Michael Edward Corcoran, was sentenced to eight years. He was found guilty of four counts of conspiring to produce cannabis and four counts of abstracting electricity.

Stefan-Alex Henderson Clarke, 28 and Kennedy Walk in Walworth, London, was sentenced to seven and a half years. He was found guilty of four counts of conspiring to produce cannabis and four counts of abstracting electricity.

Stuart Sollis, 51 and of Bowyer Street in Camberwell, London, was sentenced to eight years. He was found guilty of five counts of conspiring to produce cannabis and four counts of abstracting electricity.

David Heath, 48 and of Wentworth Crescent in Peckham, London, was sentenced to seven years. He was found guilty of three counts of conspiring to produce cannabis and three counts of abstracting electricity.

Colin Walls, 53 and of no fixed abode, was sentenced to six years. He had previously pleaded guilty to one count of conspiring to produce cannabis and was found guilty of two further counts of conspiring to produce cannabis and three counts of abstracting electricity.

Terrance Murphy, 47 and of Caspian Way in Purfleet, Essex, was sentenced to three years. He was found guilty of one count of conspiring to produce cannabis and one count of abstracting electricity.

Stephen Creed, 46 and of Beccles Road in St Olaves, Great Yarmouth, was sentenced to six years. He was found guilty following of one count of conspiring to produce cannabis and one count of abstracting electricity.

Andrew Prowse, 33 previously of Southampton Way in Camberwell, London, was sentenced to two and a half years. He pleaded guilty during proceedings to three counts of conspiring to produce cannabis.