The victim was a 22-year-old French woman and was discovered in a ruined former church in the mountains.
The woman, who died from loss of blood after a deep stab wound to the neck, has not yet been named.
She was wearing a pair of leggings and a sweatshirt, ANSA sources said.
Next to her was a packet of marshmallows.
Blood stains and drag marks were visible on the ground, a sign that the body had been carried inside the former chapel.
The Aosta public prosecutor’s office has opened a murder file on the discovery of the girl’s body in the ruined church in the hamlet of Equilivaz, above La Salle.
ANSA