The mother of Amanda Knox, jailed for murdering her British flatmate in Italy, said new forensic evidence presented in court has exposed "glaring errors" in the investigation which led to her daughter's conviction.
Experts identified more than 50 alleged mistakes in the probe into Meredith Kercher's death and said police working on the case handled vital material wearing dirty gloves. Their findings have bolstered hopes for Knox's relatives who believe her release from prison is now "more and more" likely.
An appeal hearing in the hillside town of Perugia was told that key evidence was unreliable and possibly contaminated.
During Knox's trial, prosecutors said her DNA was found on a kitchen knife while that of Miss Kercher was discovered on the blade of the alleged murder weapon.
But the independent experts - appointed by the court to review the evidence and the procedures used to obtain it - said the knife had not been properly sealed after it was found at the house of Knox's ex-boyfriend Raffaele Sollecito, opening the way to possible contamination.
Carla Vecchiotti, a forensic specialist from La Sapienza University in Rome, said it was impossible to say whether the British student's DNA was found on the knife. "There is a complete genetic profile, but it's not reliable," she said. "We don't know if Meredith's DNA was on it or not."
Knox's mother Edda Mellas said relatives are increasingly convinced that the 24-year-old will be freed on the conclusion of her appeal. "We are feeling more and more that that's going to happen," she told Sky News. "I think the appeal overall has been going great.
"They've been showing all the glaring errors that were made and no matter how hard today the prosecution tries to muddy the waters, the fact that the simplest question was, 'can you say that this was Meredith's DNA?' and the expert said, 'absolutely not, you cannot say that'."
Knox, who appeared weary as she arrived in court wearing a pink jumper, has continuously protested her innocence. "It's really hard for Amanda," Mrs Mellas said. "She's innocent, she's locked up and to have all these delays, it's horrible for her. The hardest part is watching her suffer."
The American student was convicted of sexually assaulting and murdering Miss Kercher from Coulsdon, in Surrey, at the apartment the two shared in Perugia in 2007. She was later handed a 26-year prison term while her ex-boyfriend, Italian Raffaele Sollecito, 27, was convicted of the same charges and sentenced to 25 years. Both deny wrongdoing.