Police have closed a homicide investigation into the death of a woman whose body was found on the verge of a road in the Perth suburb of St James, saying there was no foul play.

The 46-year-old's death has been deemed non-suspicious and is understood to have been the result of a medical condition.

A man who was assisting WA Police with their inquiries has been released from custody.

He had earlier been handcuffed at the scene and had paper bags placed around his hands.

It is understood the woman was found on the grass verge outside a property at the intersection of Burlington Street and Alday Street just after 3:00pm yesterday.

Police cordoned off the four streets leading to the intersection.

Homicide Squad Detectives, St John Ambulance and forensic crews were called to the scene and remained there for several hours.

A report will be prepared for the coroner.