Posted , updated
The woman experienced medical issues shortly after undergoing a random breath test in Mount Tarcoola. (ABC Midwest & Wheatbelt: Brianna Melville)
In short:
Police are investigating a woman's sudden death after a random breath test in Geraldton.
The woman underwent the test in Mount Tarcoola and experienced a medical episode shortly after.
The WA Police Internal Affairs Unit is leading the investigation into the incident.
Police are investigating a woman's sudden death after a roadside breath test in Western Australia's Midwest.
Geraldton Police were conducting random breath testing on Brand Highway in Mount Tarcoola, about 400 kilometres north of Perth, when the woman, aged in her 50s, was stopped just before 7pm on Monday.
A WA Police spokesperson said the woman was issued a driving prohibition notice and released from custody.
"Shortly afterwards, the woman began experiencing a medical issue," the spokesperson said.
"Police offered assistance; however, the offer was declined. As a precaution, officers contacted St John WA.
"A short time later, the woman became unresponsive."
Geraldton police were conducting random breath testing on Brand Highway. (ABC News: Sissy Reyes)
The spokesperson said officers at the gave the woman first aid until paramedics arrived about 10 minutes after the initial call from police.
A St John Ambulance spokesperson said the woman was taken to Geraldton Regional Hospital under priority one conditions, arriving just after 8.20pm, but was later declared dead.
Police said the incident was being treated as a death in police presence, with the Internal Affairs Unit overseeing the probe.
A report will be prepared for the coroner.