A NSW woman's reasoning for allegedly having drugs in her system while driving has been dismissed by police.
The driver was pulled over in Oran Park, southwest Sydney, on Friday evening where she underwent random testing for alcohol and drugs.
She returned a positive reading for cannabis, leading to her arrest.
However the 21-year old informed officers the drug was prescribed for pain management.
"So it's allowed," she reportedly told police, according to the Traffic and Highway Patrol Command.
However her reasoning was rejected by officers and she was taken to Narellan police station where she underwent further testing.
A second test was again positive for cannabis and has since been sent to a laboratory for examination. The driver is expected to be charged with driving with an illicit prescribed restricted substance in her system.
Her licence was suspended for 24 hours and the driver has since been released from custody.
NSW Police reminded drivers medically prescribed drugs "do not automatically give drivers the right to continue driving" when in use.
According to NSW Centre for Medicinal Cannabis Research and Innovation, cannabis medicines "can cause impairment and effect fitness to drive".
Drivers using medicines containing delta-9-tetrahydrocannabinol (THC) cannot get behind a wheel while those using medicines with only cannabidiol (CBD) present can but only in certain circumstances, with the risk posed to be discussed with their doctor.
The woman's charges were shared to Facebook, with hundreds of people commenting on the post, many believing the law to be excessive and others called for more clarity.
Earlier this month an alleged alcohol-impaired man was charged after he took a lawnmower for a ride in public.
Do you have a story tip? Email: email@example.com.