Operation Mayfly: Geoff Whelan and Emma Clarke Prosecute Large-Scale Drug Production Conspiracy

Geoff Whelan and Emma Clarke, instructed by the CPS North West Complex Case Unit, acted for the prosecution in Operation Mayfly, a case involving large-scale drug production and firearms offending. The trial was heard at Bolton Crown Court over eight weeks and concluded in November 2025, with the defendants sentenced in January 2026.

The prosecution case demonstrated that the group operated a highly organised, industrial-scale drugs manufacturing enterprise, alongside involvement in the supply of firearms and ammunition.

The evidence presented showed that the group was capable of producing up to 6 million counterfeit tablets per month, manufactured using specialist equipment at two dedicated premises. The tablets were designed to resemble diazepam-type medication and were distributed through an established supply network.

The investigation began following evidence obtained from the EncroChat communications system. Messages and images linked to one defendant showed the facilitation and supply of firearms including AK‑47s, an Uzi, Tec‑9s, a Scorpion, a Grand Power pistol, silencers, and ammunition. The messages also showed the orchestration of the industrial‑scale production of counterfeit diazepam tablets containing etizolam.

On 1st April 2022 surveillance officers observed a significant consignment being transferred to a customer. The recipient vehicle was subsequently stopped on the M61, where officers recovered over 2.5 million tablets produced by the group. That single seizure was assessed as having a street value of at least £1 million.

Expert evidence relied upon by the prosecution concluded that, over a two-year period, the scale of production attributable to the group had the potential to generate a top-end street value of approximately £288 million, illustrating the breadth and seriousness of the criminal operation.

The case required the careful presentation of extensive surveillance material, expert evidence and financial analysis, reflecting the complexity of modern organised crime prosecutions.

Following conviction after trial:

• John Eric Spiby (Senior) was sentenced to 16 years and six months’ imprisonment for conspiracy to produce and supply Class C controlled drugs, possession of firearms and ammunition, and perverting the course of justice.
• John Colin Spiby (Junior) received a sentence of nine years’ imprisonment for conspiracy to produce and supply Class C drugs.
• Lee Drury, who entered guilty pleas during the trial , was sentenced to nine years and nine months’ imprisonment for conspiracy to produce and supply Class C drugs.

A fourth defendant, Callum Dorian, had previously pleaded guilty and was sentenced in September 2024 to 12 years’ imprisonment for offences relating to drug production and the supply of firearms.