A Norfolk man is among a gang who have been jailed for a total of 90 years after being involved in the biggest conspiracy to cultivate cannabis ever uncovered in the UK.

Eastern Daily Press: 12 of the men jailed for multi-million pound cannabis conspiracy. Picture Kent Police12 of the men jailed for multi-million pound cannabis conspiracy. Picture Kent Police (Image: Archant)

The gang produced 'industrial quantities' of cannabis with a street value of more than £50m a year after setting up a string of drugs farms, including one at North Walsham which was the largest cannabis factory ever uncovered in Norfolk. A total of 16,428 cannabis plants were seized from all the sites, which also included Rochester and Sittingbourne in Kent, which the prosecution said gave an estimated street value for a single year of between £25,418,160 to £51,852,840.

Fourteen members of the gang, which included Stephen Creed, of Beccles Road, St Olaves, Great Yarmouth, were jailed for a total of 90 years at the Old Bailey on Thursday.

It followed a complex joint operation involving Norfolk police and the Kent and Essex Serious Crime Directorate which started with the discovery of the first factory on Rochester High Street on June 28, 2013.

Bearded Creed, who was jailed for six years, was found with 6.5kgs of cannabis in heat-sealed bags in his toilet.

Eastern Daily Press: Cannabis farm in Laundry Loke, North Walsham . Picture Kent PoliceCannabis farm in Laundry Loke, North Walsham . Picture Kent Police (Image: Kent Police)

Jailing ringleader Michael Edward Corcoran for 14 years, Judge Dhir said: 'You were the head of this crime group.

The judge sentenced Corcoran's close friend and 'second in command' David Graham for nine-and-a-half years. James Allen, a 'primary mover and trusted right hand man', was jailed for seven years. Stephen Macey, who was recruited by Corcoran after growing close to his daughter, was jailed for six years. Michael Jay Corcoran, was jailed for eight years. Henchman Stefan-Alex Henderson Clarke, was jailed for seven-and-a-half years after providing security for the cannabis factories.

Errand boy Andrew Prowse was jailed for two-and-a-half years. Drug addict Stuart Sollis was jailed for eight years. David Heath received a seven year sentence. Colin Walls, who was caught when police found a cigarette butt with his DNA on it at a cannabis factory, was jailed for six years. Terrance Murphy was jailed for two-and-a-half years. Christopher Marsh was jailed for four years. The youngest gang member Damon Mills was sentenced to 18 months in a young offenders' institution.

Eastern Daily Press: Laundry Loke, North Walsham. Picture : ANTONY KELLYLaundry Loke, North Walsham. Picture : ANTONY KELLY (Image: archant 2017)

'The operation was complex and time consuming but demonstrates that organised crime and drug trafficking networks operating in Norfolk will be targeted and closed down'

The discovery of Norfolk's largest ever cannabis factory was part of the biggest conspiracy to cultivate the class B drug uncovered in the UK.

For two years they produced 'industrial amounts' of cannabis worth more than £25m a year from sites in North Walsham in Norfolk and Rochester and Sittingbourne in Kent.

Eastern Daily Press: Cannabis farm in Gravesend. Picture Kent PoliceCannabis farm in Gravesend. Picture Kent Police (Image: Kent Police)

A total of 16,428 plants were seized across the locations which were each set up, almost identically, with purpose-built two-storey wooden constructions created inside industrial units.

Fourteen members of the gang are today starting jail sentences totalling 90 years after justice caught up with them.

It followed a complex joint operation involving Norfolk police and the Kent and Essex Serious Crime Directorate which started with the discovery of the first factory on Rochester High Street on June 28, 2013 following reports of a burglary.

The rear door had been forced and police discovered a large cannabis production inside. The total amount of cannabis plants seized from Canal Basin was 9,888.

Eastern Daily Press: Cannabis farm in Sittingbourne. Picture Kent PoliceCannabis farm in Sittingbourne. Picture Kent Police (Image: Kent Police)

As a result of police surveillance, Michael Edward Corcoran, Graham, Macey, Terrance Murphy and Stephen Creed were seen at the Laundry Loke warehouse in North Walsham in late 2015.

The Laundry Loke Unit was leased for a seven year period on October 9, 2014 by David Graham using false details.

On October 26 2015, police searched Laundry Loke.

The premises had been divided into numerous rooms which contained equipment and cannabis. A total of 1,907 plants were seized. The potential annual street value of these drugs would have been in excess of £3m.

Eastern Daily Press: Cannabis farm in Gravesend. Picture Kent PoliceCannabis farm in Gravesend. Picture Kent Police (Image: Kent Police)

An electrician confirmed the power supply been tampered with and the meter bypassed. The total estimated loss of electricity was in the region of £30,000.

Detective Inspector Tom Smith, from Norfolk police, said: 'This was the largest cannabis factory ever discovered in Norfolk during a joint operation with Kent and Essex Serious Crime Directorate. The operation was complex and time consuming but demonstrates that organised crime and drug trafficking networks operating in Norfolk will be targeted and closed down. These convictions also highlight how forces across the country work together to tackle organised crime.'

Shocked neighbours had no idea

Eastern Daily Press: Cannabis farm in Gravesend. Picture Kent PoliceCannabis farm in Gravesend. Picture Kent Police (Image: Kent Police)

Businesses neighbouring the industrial unit have described how the business was 'very well disguised'.

Chris Newnham, managing director of Newnham Structures, owns the unit directly beside the old factory.

He said: 'We had no idea. The first thing we knew about it was when we turned up on a Monday morning and there were police and sniffer dogs everywhere.

Eastern Daily Press: Cannabis farm in Gravesend. Picture Kent PoliceCannabis farm in Gravesend. Picture Kent Police (Image: Kent Police)

'My staff never reported any strange smells to me and we saw very little as most of what they were doing happened at night.'

An employee of another neighbouring business, TC Tyres, said: 'We used to see the occasional small van or two go past the yard and into the building but other than that we hardly saw anyone.

'We had no clue what was going on. We're here 8am-5pm most of the time and because they were operating at night we didn't see anything. The first we knew of it was when the police turned up.'

Eastern Daily Press: Cannabis farm in Gravesend. Picture Kent PoliceCannabis farm in Gravesend. Picture Kent Police (Image: Kent Police)

Charges and pleas

• James Allen, of Woolwich Road, Abbey Wood, southeast London, pleaded guilty to five counts of conspiring to produce cannabis and three counts of abstracting electricity.

• Stephen Macey, of Commercial Road, Paddock Wood, Kent, pleaded guilty to five counts of conspiring to produce cannabis and five counts of abstracting electricity.

• Christopher Marsh and Damon Mills, both of Ethelbert Road, Margate, Kent, admitted one count of conspiring to produce cannabis and one count of abstracting electricity.

• In November 2016 Michael Edward Corcoran, of Mount Avenue in Yalding, was convicted of seven counts of conspiring to produce cannabis and five counts of abstracting electricity.

• Michael Jay Corcoran, of Odo Rise in Gillingham, Kent, Stefan-Alex Henderson Clarke, of Kennedy Walk in Walworth, southeast London, were convicted of four counts of conspiring to produce cannabis and four counts of abstracting electricity.

• Stuart Sollis, of Bowyer Street, Camberwell, southeast London, was convicted of five counts of conspiring to produce cannabis and four counts of abstracting electricity.

• David Heath, of Wentworth Crescent, Peckham, southeast London, was convicted of three counts of conspiring to produce cannabis and three counts of abstracting electricity.

• Colin Walls, of no fixed address, 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, of Caspian Way, Purfleet, Essex, was convicted of one count of conspiring to produce cannabis and one count of abstracting electricity.

• Stephen Creed, of Beccles Road, St Olaves, Great Yarmouth, was convicted of one count of conspiring to produce cannabis and one count of abstracting electricity.

• David Graham, of Plaistow Lane, Bromley, pleaded guilty to five counts of conspiring to produce cannabis and five counts of abstracting electricity before his trial.

• Andrew Prowse, of Southampton Way, Camberwell, southeast London, pleaded guilty to three counts of conspiracy to produce cannabis during his trial.

• Alan Marquiss, of Disraeli Close, Thamesmead, southeast London, pleaded guilty to one count conspiracy to produce cannabis and one of conspiracy to abstract electricity between 1 October 2014 and 15 December 2015.