The smugglers, who brought the 'skunk' into Britain hidden in boxes of flowers from Holland, are believed to have made an estimated £62million.
At one point, the gang was shipping in consignments worth up to £750,000 a week and would use an East London bureau de change to clean up its 'dirty' profits.
Terrence Bowler will be sentenced, along with 11 others, at Southwark Crown Court in London for his leading role in what is believed to be Britain's most prolific skunk cannabis-smuggling rings.
Neatly stacked wads of cash illustrate the scale of the cannabis ring's wealth
Bags of skunk weighting more than 220 kilogrammes were found within the shipment at Harwich belonging to members of the gang believed to be Britain's most prolific importers of skunk cannabis
Details of the case can be reported for the first time today for legal reasons.
A 14-month undercover investigation found that the drugs were imported into the UK through Harwich ferry port in Essex and taken to a warehouse in Chatham, Kent.
But officers at the port intercepted a shipment of 224kg, worth more than £750,000, on July 16, 2008, prompting a major change in tactics.
From September 2008, the drugs were shipped to Hull and taken to a warehouse in Leeds, West Yorkshire, before being transported to one of a number of lock-up garages in Kingston, Worcester Park, Epsom and Ashtead, where the skunk cannabis would be unpacked and stored.
More than £60,000 that was found within the safe at Deer Park Close that had gone mouldy
Drugs were even hidden inside deliveries of fresh flowers
Bowler, 40, from Kingston, Surrey, Peter Moran, 37, from Fulham, west London; and Mark Kinnimont, 40, from Surbiton, Surrey, made up the board of directors and all pleaded guilty to conspiracy to import controlled drugs and conspiracy to launder the proceeds of crime.Liam Salter, David Couchman and Timothy Sullivan represented the next level of authority.
Asim Bashir, 35, from Ilford, Essex, made sure that the drug money was included with legitimate cash and laundered through the financial system.
He was convicted of laundering the proceeds of crime.
Gang member Peter Brown is seen unloading drugs at a lock up in Marlborough Gardens belonging to the gang
Roger Alexander, 44, from High Wycombe, Buckinghamshire, sold much of the imported product, earning £150 to £175 per kilo, and admitted conspiracy to supply controlled goods and conspiracy to launder the proceeds of crime.He was witnessed meeting dealer Barrie Burn, 59, from Bristol, and both men pleaded guilty to conspiracy to supply controlled drugs.
Andrew West, 36, from Tadworth, was a driver for the gang and pleaded guilty to conspiracy to launder the proceeds of crime.
Hay, 31, from Ashtead, was remanded in custody by Judge Gregory Stone QC and told he must expect a custodial sentence.
Mandy Cripps, 34, from High Wycombe, Richard Seville, 42, from Islington, north London, Peter Gilmour, 36, from High Wycombe, and Lindsay Graham, 42, from Sutton, Surrey, were cleared of any involvement in the gang earlier this week.
All the convicted defendants will be sentenced 'within two or three weeks', the judge said.
The gang: Terrence Bowler, Peter Moran, Mark Kinnimont and Liam Salter, with (from left bottom row) David Couchman, Timothy Sullivan, Asim Bashir and Roger Alexander, members of a ang believed to be Britain's most prolific importers of skunk cannabis who were facing jail today