John Keet, 41, of Chalfont St Giles, was described as the ringleader of a sophisticated drug dealing operation by National Crime Agency (NCA) investigators.
The NCA says that Keet invested profits from a career dealing cocaine, cannabis and amphetamines into building and managing a giant lab.
He paid for his right hand man, Keith Davis, 62, also of Chalfont St Giles, to undergo chemistry training to enable him to operate the site, investigators say.
To uncover Keet and Davis’ operation, the NCA investigators identified encrypted messaging platform EncroChat, which led them to a factory laboratory near Redditch.
Andrew Gurney, 51, of Quinton, Birmingham, was known as ‘The Geek’ due to his specialist electrical installation and plumbing skills, the NCA reveals.
He converted what had been a double garage outbuilding into the drugs lab.
He completed the same chemistry training course as Davis.
Davis was jailed for five years and three months and Gurney to six years and three months at Kingston Crown Court today (10 June).
Keet is due to be sentenced on 22 August.
Work started on the building in March 2020 and it began producing drugs in May of that year.
An NCA spokesman said: “The gang initially bought amphetamine precursor chemical benzyl methyl ketone (BMK) but quickly realised it was more profitable to make it themselves.”
NCA officers raided the site in Ullenhall Lane, Henley-in-Arden, Warwickshire, on 27 April last year, with assistance from Warwickshire Police.
The spokesman added: “Plumes of noxious fumes billowed from the outbuilding when it was opened by specialist crews from West Midlands Fire Service, who had to wait several hours before searching it due to the hazardous chemicals inside.
"Waste products from the production process, which had been flushed into the sewerage system, had also contaminated a nearby field.”
The NCA’s investigation formed part of Operation Venetic, the UK law enforcement response to the July 2020 takedown of the EncroChat encrypted communication service.
NCA branch commander Matt McMillan said: “Keith Davis and Andrew Gurney had key roles in running one of the largest drugs laboratories ever found in the UK.
“Under the direction of John Keet, they meticulously planned this criminal enterprise – even undergoing chemistry training to run the laboratory.
“The drugs produced will have fuelled violence, fear and exploitation in communities across the UK.
“Closing down this lab is a great example of multi-agency cooperation to protect the public.”
The gang members were all arrested on suspicion of drug offences at their home addresses on the same day.
Electronic weighing scales were found in Davis’ home, along with 300 kilos of BMK at a storage facility he had access to.
A number of documents and receipts were found in Gurney’s vehicles, The NCA states.
These related to heating equipment identified in the lab, weighing scales and chemicals needed for amphetamine production.
Officers also found PPE, including respirators and wellington boots which had chemical traces of amphetamine on them.
Davis and Gurney were convicted at Kingston Crown Court on Tuesday (8 June), following a 12-day trial.
Keet pleaded guilty to all the charges at the same court on 29 October last year.
Elliott Walker, 49, of Kidbrooke, south London, was an associate of Keet and purchased specialist equipment for the lab.
He pleaded guilty to conspiracy to produce class B drugs (amphetamine) on 17 September last year and was jailed for six years on 14 December.