Prisoners use shampoo and the “zombie drug” spice to get high while inside a Hertfordshire prison, a coroner’s report has suggested.

An inquest after the death of an inmate found drugs and alcohol are “widely available” at HMP The Mount in Bovingdon, and there is a “significant risk of future deaths” at the prison.

Assistant coroner Jonathan Stevens has ordered prison governor John Gormley and justice secretary Alex Chalk MP to come up with an action plan for the prison near Hemel Hempstead.

Mr Stevens’ direction follows the death of Kristopher Tilbury, who died in his cell aged 29 between September 23 and September 24, 2019.

Tilbury suffered “respiratory depression” – hypoventilation – after combining alcohol with synthetic cannabinoids, drugs also known as spice.

The prisoner, who was serving an eight-year sentence, was on the Wellbeing Wing after he “recognised and accepted” drug and alcohol issues were linked with his offending.

“He was found with a mobile phone in his hand and drug paraphernalia nearby in his cell with the smell of [redacted] in the air,” Mr Stevens’ Prevention of Future Deaths Report, dated September 2023, reads.

“The jury also recorded that despite Mr Tilbury’s known drug and alcohol issues and residing on the prison’s additionally supported Wellbeing Wing, drug paraphernalia was found in his cell including [redacted] and evidence of shamboiling.”

Shamboiling reportedly involves boiling shampoo to get high, according to a viral 2012 CNN iReport story.

A CNN producer was unable to verify the practice existed at the time, but warned using any household product to get high is “incredibly dangerous”.

HM Inspectorate of Prisons picked up a drugs problem at The Mount in May 2018, 16 months before Tilbury’s death.

Inspectors found “levels of violence were comparatively high and most related to drugs and debt”.

Fewer than half of the required intelligence-led searches were completed and most suspicion drug tests were missed.

Mandatory drug testing indicated nearly a third of prisoners were using illegal drugs.

In his report, the coroner made reference to four more deaths at HMP The Mount since September 2019 – two in July 2022 and two in January 2023.

“Four years after the death of Mr Tilbury, drugs and alcohol are still widely available in HMP The Mount, and continue to create a significant risk of future deaths,” Mr Stevens concluded.

Writing directly to Mr Gormley and Mr Chalk, Mr Stevens said: “In my opinion, action should be taken to prevent future deaths and I believe you and/or your organisation have the power to take such action.

“You are under a duty to respond to this report within 56 days.

“I, the coroner, may extend the period.

“Your response must contain the details of action taken or proposed to be taken, setting out the timetable for action.”

HMP The Mount is a closed prison for adult males with around 1,000 inmates.

A visit by HM Inspectorate of Prisons in February 2023 found The Mount teams had made “no meaningful progress” to reduce harm and the likelihood of reoffending since May 2018.

A Prison Service spokesperson said: “Our thoughts remain with the family and friends of Kristopher Tilbury and we will carefully consider the coroner’s findings.

“HMP The Mount is taking decisive action to combat drugs in the prison including reintroducing mandatory drug testing and ramping up searches.

“We have also invested £100million into tougher security measures across the prison estate – such as X-ray body scanners – to find and stop more contraband entering jails.”