New testing of traces of DNA on the kitchen knife allegedly used to kill Meredith Kercher shows that it belonged to Amanda Knox rather than the British student, suggesting that the knife may not have been the murder weapon at all.
The results were released on the eve of the sixth anniversary of the murder of Ms Kercher, who was found dead in a pool of blood in the hillside cottage she shared with Ms Knox and two Italian women on November 2, 2007.
The knife was confiscated by police from the flat of Ms Knox's then boyfriend, Raffaele Sollecito, and her defence lawyers said it was only natural that it may have carried traces of her DNA because she used it to cook meals.
The results of the tests have been hailed as a victory by Ms Knox's team of defence lawyers, who are seeking to prove her innocence at a third trial, this time in Florence.
The American, who has resumed her studies at the University of Washington in Seattle, has elected not to attend the retrial, but Mr Sollecito is expected to attend for the first time at the next hearing, on Wednesday.
At the original trial of Ms Knox and Mr Sollecito in Perugia in 2009, forensic experts said that a DNA trace on the blade of the knife belonged to Ms Kercher and that another trace on the handle was that of Ms Knox.
Prosecutors used the evidence to claim that the American had used the kitchen knife to murder her British housemate. (©Daily Telegraph, London)