Ms Hartley said Mr Deavall and his cellmate had been locked in their cell when he was taken ill.
The cellmate pressed the emergency cell bell but a non-VP (Prisoner A) talking with two other prisoners on the landing deactivated the bell on the panel outside the cell before resuming his conversation.
A minute elapsed before he alerted prison officers about the medical emergency.
Ms Hartley said staff were alerted “more by accident than design depending as it did on the caprice of Prisoner A”.
Ms Hartley added: “There remains a risk that future deaths could occur as it remains the case that emergency cell bells at HMP Forest Bank can be deactivated readily and altogether by other prisoners and no action to implement fail-safe measures is currently proposed.”
The coroner wrote to the operator of the private jail, Sodexo Justice Services, along with Spectrum Community Health CIC and Med-Co Secure Health Services Ltd stressing “urgent action should be taken to prevent future deaths and I believe your organisations have the power to take such action”.
Her report was also sent to the Prison and Probation Ombudsman and His Majesty’s Inspectorate of Prisons.
An HMP Forest Bank spokesman said: “Our thoughts and condolences remain with Mr Deavall’s family.
“Following the close of the inquest, we are working with His Majesty’s Prison and Probation Service and the Ministry of Justice to review the coroner’s conclusions and recommendations.”
