The case highlights the need for clear and consistent guidance on driving when prescribed medical cannabis.
Last week, the first official guidance on medical cannabis for police officers in England and Wales was made public.
The National Police Chiefs' Council has approved the first official guidance for medical cannabis.
The study found that 88% of participating officers knew little or nothing about the regulations before taking part in the training.
The vast majority (89%) of police officers surveyed said they believed they would benefit from more training on medical cannabis.
