A police force is training staff on the risks of choking after a coroner hit out at the "complete lack of knowledge" shown in an arrest in which a man died.
Drug dealer Karl Brunner, 48, swallowed heroin as he was being detained in Bedford in 2016, and died in hospital.
Coroner Ian Oldham called for "urgent" action from police to prevent future deaths.
Bedfordshire Police said it had brought in "comprehensive" training for all staff on detainees who were choking.
The inquest last January heard Mr Brunner, of Clarendon Road, Bedford, was apprehended near a bus station in a planned drug stop based on intelligence.
As police tried to handcuff him he appeared to become unconscious after being heard to faintly say "I can't breathe", but because of a number of factors "could not be heard by human ear".
Officers then attempted CPR before he was taken to hospital, where he died. A jury found his death was accidental.
In his recently-published preventing future deaths report to police, Mr Oldham said "officers were trained to deal with suspects who had swallowed drugs".
He continued: "The evidence however disclosed a complete lack of knowledge of the risks of choking when suspects were either arrested or in the process of being detained.
"This should urgently be addressed in the officers' training and the appropriate medical procedures should be adopted."
Mr Oldham said mouth and face guards given to officers were "so defective and inappropriate when dealing with high-risk suspects who may have significant health issues that they are neither carried nor used in appropriate cases".
The inquest heard Mr Brunner, a known drug user, had vomited and had blood around his mouth at the time, which made it difficult for paramedics to establish an airway in the minutes before his death.
Bedfordshire Police said staff were now receiving up-to-date first aid training, and all officers had a personal pocket face mask.
"The training includes a specific comprehensive module on dealing with a choking detainee which includes specific instructions should an officer or custody staff be faced with a similar scenario to that which occurred during the detention of Mr Brunner," a spokesman said.