Kercher murder knife is wrong weapon, says expert

Prosecutors allege that Meredith Kercher was killed during what had begun as a sex game (AFP/Getty )

The knife police say killed British student Meredith Kercher could not have been used to cut her throat, a forensic expert told a court today.

The blade, which had traces of both Ms Kercher's DNA and that of her accused killer American Amanda Knox, was too long to be the weapon, defence witness Carlo Torre said.

Knox and her Italian former boyfriend Raffaele Sollecito are both accused of murdering Ms Kercher, 21, from Coulsdon, Surrey, at the apartment she shared in Perguia, Italy in November 2007. Both deny the charges.

Prosecutors allege that Miss Kercher was killed during what had begun as a sex game.

Mr Torre told the hearing today the neck wound was made with a knife with a 3-inch long blade, while prosecutors maintain a 6 1/2-inch knife found at Sollecito's home could be the murder weapon.

He also said there was no evidence that Ms Kercher was assaulted by more than one person.