Prison Guard Jason Thompson Jailed: HMP Isis Smuggling Plot

Published: 3 April 2026 . The English Chronicle Desk. The English Chronicle Online—Exposing the networks that compromise the security of the British prison estate.

A major criminal network that used a “corrupt insider” to flood a London prison with drugs, phones, and pornography has been dismantled, with its members jailed for a combined total of 25 years. Following a meticulous investigation by the Metropolitan Police’s Specialist Crime Unit, former prison officer Jason Thompson and his accomplices were sentenced at Snaresbrook Crown Court on Thursday, 2 April 2026. The plot, which operated for six months, represents one of the most significant breaches of prison security in recent years.

The investigation into the 34-year-old Thompson began in February 2024 after the Prison Service flagged suspicious activity at HMP Isis in South East London. Detectives soon uncovered a web of communication between Thompson and a North London-based organized crime group.

The Intermediary: Thompson acted as the vital link, using a burner phone to coordinate with the gang outside. For his role in the conspiracy, he was paid between £400 and £600 per package delivered.
The “Drop-Offs”: Between February and July 2024, the group was responsible for 18 successful deliveries. The gang utilized the prison’s booking system to arrange “supervised visits,” during which contraband was surreptitiously passed to Thompson or directly to inmates.

The scale of the operation was revealed when officers intercepted a package in March 2024 containing cannabis resin. Subsequent raids across 11 London addresses uncovered a “retail-style” inventory intended for the prison black market:

Narcotics: Large quantities of cannabis, vape oil, and Class A drugs.
Technology: Over 100 mobile phones and SIM cards, which allow inmates to continue directing criminal activity from behind bars.
Media: USB sticks pre-loaded with entertainment and pornographic material, a high-value commodity in the restricted prison environment.
Ammunition: During the house raids, police also seized live ammunition, highlighting the violent nature of the gang involved.

In court, Thompson pleaded guilty to conspiracy to convey List A articles into prison and misconduct in a public office. He was sentenced to four years and six months in prison. The gang’s ringleader, 26-year-old Olusegan Shobanjo, and several other members received sentences totaling over 20 years.

Detective Inspector John Cowell, who led the operation, issued a stern warning to those tempted by the “easy money” of prison corruption. “The members of this gang believed they could outsmart both the police and prison authorities,” he said. “What they did not realize was that we had identified the conspiracy early on and were building a case that would ultimately bring them to justice.”

Deputy Governor Stephen Forde of HMP Isis reinforced that while the vast majority of staff are “honest and hardworking,” those who choose corruption “put staff and prisoners at risk and damage public trust.” As Thompson trades his officer’s uniform for a prisoner’s jumpsuit, the case serves as a stark reminder of the ongoing battle to maintain the integrity of the UK’s correctional facilities.

Operation Inventory: HMP Isis Smuggling Ring (2024–2026)

Asset Seized	Estimated Prison Value	Status
Mobile Phones	£50,000 – £75,000	Confiscated
Cannabis Resin	High Street Value x 5	Confiscated
USB Media Sticks	High Demand/Barter	Confiscated
Ammunition	N/A (Safety Risk)	Confiscated
Bribe Payments	£10,000+ (Est. Total)	Tracked/Seized