A pensioner died within two hours of being arrested by police who thought he was drink-driving.
Motorist Anthony Brown was sober but was suffering diabetic symptoms, which are similar to the effects of alcohol.
An inquest at Ashford heard the two officers who took him in had virtually no knowledge of diabetes, with one having no first aid training for 25 years.
It was only at Ashford Police Station that he revealed his illness and an ambulance was immediately called, the two-day hearing was told.
But Mr Brown also suffered a heart attack at the station and died in hospital.
The tragedy happened on December 20, 2007 when Mr Brown, 71, of Sandyhurst Lane, Ashford, had taken the wrong turning in his car and wandered up to cones the shared space roadworks at Tufton Street.
Workmen told him to reverse out but his condition meant he could no longer work the car.
It was then that Sgt Mark Wells and PC David Cox appeared and arrested him on suspicion of driving while under the influence of drink or drugs.
They found he was red-faced, his speech was slurred, he was unsteady on his feet and was unable to control the car.
These were symptoms of diabetes and a post mortem examination later proved Mr Brown had not been drinking.
Kent Police launched an internal investigation but concluded that while the actions of the officers involved may have shown poor judgement they were not negligent.
No disciplinary action will be taken against them and paramedics had praised the efforts of police to save Mr Brown once they realised his true condition.
The inquest heard that Kent Police has now expanded first aid training, to provide tuition on diabetes awareness to both trainee and seasoned officers.
Pathologist Dr David Rouse said Mr Brown’s condition was so severe he was likely to have died even if not arrested.
A jury returned a verdict of natural causes.
For more news from Ashford, Folkestone, Hythe and Tenterden visit kentishexpress.co.uk >>>