Amanda Knox says she wrote unsent letter to Meredith Kercher's family Amanda Knox in an interview with ABC News's Diane Sawyer, in New York. Photograph: Ida Mae Astute/AP Amanda Knox has said she wrote to the parents of her murdered flatmate, Meredith Kercher, insisting she had not killed their daughter - but the letter was never sent. The American, who once more faces accusations that she was involved in the killing, was advised by lawyers that sending the letter could harm her defence. Knox's desire to communicate with the Kercher family is disclosed in her book, Waiting To Be Heard, which is published in the US on Tuesday. In an extract seen by The Sun she tells how she wrote to the Kerchers. I'm not the one who killed your daughter and sister. I'm a sister too and I can only attempt to imagine the extent of your grief. In the relatively brief time that Meredith was part of my life, she was always kind to me. I think about her every day. Her lawyers told her, though, that it was "not the right time" to send the letter. Last month, Italy's highest criminal court overturned Knox's acquittal for the murder of Leeds University student Kercher, from Coulsdon, Surrey, in Perugia, Italy in November 2007. Knox returned to her home in Seattle after she was dramatically cleared in 2011 following four years in jail. She faces the prospect of an extradition request from the Italian government and a new trial in Florence. Kercher, 21, was found with her throat slashed in her bedroom at the house she shared with Knox. Prosecutors claimed she was the victim of a drug-fuelled sex game gone awry. Knox and her Italian ex-boyfriend Raffaele Sollecito, 29, denied wrongdoing. They were convicted following a high-profile trial but were released after an appeals court found the prosecution lacking and criticised large swathes of the case against them. Italian law cannot compel Knox to return to the country for a fresh trial but she could eventually face an extradition request. It would then be up to the US to decide if it honours it. Knox and Sollecito have consistently protested their innocence and claim they were not even in the apartment on the night Kercher died. The case mounted against them by prosecutors was ripped apart by the Italian appeals court which noted the murder weapon was never found, DNA tests were faulty and that prosecutors provided no motive for murder. Rudy Guede, a small-time drug dealer from the Ivory Coast, is the only person who remains behind bars over the case, where he is serving a 16-year sentence for sexually assaulting and killing the British student. He has always admitted being present at Kercher's cottage on the night of the murder, but denied involvement.