A scene is currently in place at Culver Street Car park, Salisbury, following the discovery of a body.
Wiltshire Police said in a statement: "We were contacted at around 10pm last night (13/04) after a woman in her 40s was found unresponsive.
"Despite the best efforts of the emergency services she was declared dead at the scene.A scene has been put in place while we conduct our enquiries.
"A man in his 20s has been arrested on suspicion of manslaughter.
"While we understand the public concern that this may cause, there is no wider threat to the public."
A scientific investigations team have been working in the car park this afternoon following the discovery last night.

Catastrophic Bleed Kits Installed at ALABARÉ Homes During Knife Crime Awareness Week
Wiltshire Council celebrates 50,000 children trained through Bikeability programme
Walk for Wards passes 1,000 sign-ups
New community logo launched for Amesbury
Museum re-opens after major refurb
SWR warns passengers over hot weather
Workshop planned for young people interested in architecture and design
Salisbury captain signs on for another season
