The woman was discovered by her boyfriend around 8.30pm and had visible injuries to her body.
How the injuries occurred and why the woman was lying outside remains unknown.
“Because we don’t know under what conditions she received her injuries, we’re working two angles,” said Skövde police spokesperson Johan Rapp to the TT news agency.
“Either it was an accident, which is most likely, or it involves some sort of crime,” he said.
Police have blocked off the area to carry out a technical investigation.
As of late Sunday night there were no suspects in the case.