Amanda Knox had a list of questions she longed to ask the killer of British student Meredith Kercher in court but was denied the chance, her stepfather said.
Rudy Guede, the first person to be convicted of the 2007 murder in the Italian town of Perugia, gave evidence for the prosecution at the American's appeal hearing.
Knox, who was found guilty of killing the University of Leeds student in separate proceedings, was keen to take the opportunity to quiz him about his evidence.
But to her frustration he was escorted out of court before she could do so, Chris Mellas said.
"Amanda had a big long list of very detailed questions for him but for whatever reason the judge wouldn't allow it so it didn't happen," he said after the hearing.
Guede appeared before a packed courtroom to confirm the contents of a letter he wrote to his lawyers last year, which ends with a direct accusation against Knox and her Italian ex-boyfriend Raffaele Sollecito.
In the March 2010 letter, which was read out in court, Guede claimed he had nothing to do with the "horrible murder of the splendid and wonderful Meredith Kercher by Knox and Sollecito".
He told the court: "This is a thought I've always had in my mind. It's not up to me to decide who killed Meredith Kercher."
Guede was convicted of the murder of 21-year-old Miss Kercher, from Coulsdon in Surrey, in a fast-track trial held separately from the trial of Knox and Sollecito. He denies any wrongdoing.
Knox, 23, and Sollecito, 26, both deny wrongdoing and are fighting to overturn their guilty verdicts and their respective jail sentences of 26 and 25 years.