Prosectors in Italy have filed papers to appeal the decision to clear an American student, Amanda Knox, of murdering her British flatmate.
Ms Knox was cleared last October of the murder of Meredith Kercher in Perugia in 2007.
Prosecutors have filed a motion in Italy's highest court to appeal the verdict.
They say the acquittal was contradictory and illogical.
Miss Kercher, 21, from Croydon, London, was found semi-naked in her bedroom and with her throat cut.
She had also been sexually assaulted, leading prosecutors to believe she was killed in a brutal sex game that went wrong.
Miss Kercher was sharing a cottage in the town of Perugia in central Italy with Miss Knox, who is originally from Seattle.