ROME — A single fingerprint and a trace of blood belonging to American student Amanda Knox were found in the Perugia apartment where her British roommate was slain, but the apartment was otherwise cleaned, news reports said Wednesday.

Investigators have concluded that the blood was left on the bathroom faucet sometime between Nov. 1 and 2, the ANSA news agency reported, placing Knox in the apartment either the night her roommate died or the next morning.

Knox has acknowledged she was home the night Meredith Kercher, 21, was killed by a knife wound to the neck but has denied any wrongdoing.

Calls to Knox's attorney were not answered today.

"The visibility of the stain is such to exclude that it could have been left in the days before the crime since it would surely have been cleaned," investigating magistrate Giuliano Mignini wrote in a summary of his probe so far, ANSA reported.

Knox, 20, a University of Washington student from Seattle, has said in one of her several conflicting statements to prosecutors that she was in the apartment the night of the slaying, saying at one point she had to cover her ears to drown out Kercher's screams and returned the next day.

ANSA quoted the summary as saying that the apartment was otherwise cleaned, such that the only fingerprint of Knox found in the apartment, which she shared with Kercher, was on a glass.

Police have said both Knox and Kercher's DNA was found on a knife that they believe may have been the murder weapon; the knife was found at the home of Knox's then-boyfriend Italian Raffaele Sollecito.

In addition to Knox, Sollecito and Rudy Hermann Guede, an Ivory Coast native, have been detained in the slaying. Guede is awaiting extradition to Italy after his arrest in Germany.

A fourth suspect was recently released from jail for lack of evidence.

All four suspects deny any role in Kercher's slaying.

Guede has acknowledged that he was in Kercher's room the night she died, but said he didn't kill her and that an Italian who is trying to frame him did. DNA testing has confirmed that Guede had sex with Kercher the night of the murder.

Prosecutors have said Kercher was killed while resisting a sexual attack. Guede also has denied he attacked Kercher sexually.

Kercher family attorney Francesco Maresca said today he believed that investigators had determined that a second autopsy would not be necessary on Kercher, allowing her family to bury her in Britain, where her body was flown Nov. 11. Defense lawyers had pushed for new tests to better determine how and when Kercher died.

On Friday, a hearing is scheduled in a Perugia tribunal to determine if Knox and Sollecito should continue to be held. The judge who originally ordered them held said there was sufficient evidence to warrant their detention and that they represented flight risks.