Morel’s body was found in the woods in a bag on Thursday night, the Tribune de Genève reported.
The discovery was made in the municipality of Versoix, northeast of the city of Geneva.
Police issued a call for help on Thursday after Morel went missing while accompanying Fabrice Anthamatten, 39, who was serving a sentence at Geneva’s Champ-Dollon prison for rape.
The pair failed to show up for an equestrian therapy session scheduled for late Thursday morning.
Police said they were travelling in a white Citröen Berlingo with licence plates GE 719 149.
Anthamatten, born in France, was convicted in that country and in Geneva of separate rape charges dating back to 2001.
He was permitted to leave the Geneva prison under Morel’s escort for the purposes of “reintegrating” him into society, the Tribune de Genève reported.
A criminal investigation has been launched into the affair, the newspaper said.
Anthamatten remains at large.
The case has raised questions about how such a criminal could have been trusted to leave the prison with only a woman as an escort.
In May, convicted murderer Claude Dubois, 36, strangled Marie, a 19-year-old woman, in Payerne, in the canton of Vaud in a case that earlier raised questions about penal laxity.
Dubois, later arrested, was serving a prison sentence at home while wearing an electronic surveillance bracelet.