An Italian appeals court has overturned the murder conviction of American Amanda Knox, who four years ago was jailed for 26 years for the murder of British student Meredith Kercher.

The 24-year-old American insisted she played no part in the crime.

Her nightmare ended when jurors in her appeal trial found her not guilty of stabbing Miss Kercher after forcing her into a violent sex game.

Knox, from Seattle, was jailed for 26 years in December 2009 after a year-long trial, along with her Italian ex-boyfriend Raffaele Sollecito who was jailed for 25 years.

Sollecito, 27, was also cleared after a successful appeal.

The verdicts came after the former lovers delivered heartfelt addresses to the Perugia court this morning, proclaiming their innocence once more.

Knox, watched by her anxious family in the medieval chamber, declared: "I am not who they say I am - the perversion, the violence, the lack of respect for life - and I did not do the things they say I did. I did not kill, I did not rape, I did not steal. I was not there at the time."

Choking back emotion, she told jurors: "I want to go back to my life. I do not want to be punished. I do not want my life taken away for something that I did not do because I am innocent."

The semi-naked body of Leeds University student Miss Kercher, 21, from Coulsdon in Surrey, was found on November 2, 2007, in the house she shared with Knox on her year abroad.

Small-time drug dealer Rudy Guede, 24, from the Ivory Coast, was jailed for the murder and sexual violence after separate proceedings and, while he too protests his innocence, his conviction was upheld on appeal.