Three people are being held over the murder of Meredith Kercher
Briton Meredith Kercher may not have been raped before her murder, according to a new post-mortem examination.
Police had previously said there was evidence of a violent sexual encounter but the report said it was not possible to say whether she had been assaulted.
It added that a knife from a suspect's house could be the murder weapon.
Three people are being held over the murder of Leeds University exchange student Miss Kercher, 21, of Coulsdon, south London, in Italy in November.
Three pathologists confirmed the absence of any drugs in Miss Kercher's blood.
The post-mortem report will be discussed at a court hearing on Saturday with defence lawyers for the three suspects.
American Amanda Knox, Italian Raffaele Sollecito and Rudy Hermann Guede, from Ivory Coast, are being held on suspicion of sexually assaulting and murdering Miss Kercher.
Police have said they have forensic evidence linking all three suspects to the murder. The knife was recovered by officers from Mr Sollecito's home.
All three deny involvement in the student's death and have not been charged.
They have lost their last appeals to be freed, and can be held for up to a year before trial.
Miss Kercher was found dead under a duvet with her throat cut in her bedroom in the city of Perugia on 2 November.