Italy’s top appeals court has overturned the convictions of Amanda Knox and Raffaele Sollecito for the murder of UK student Meredith Kercher.
The decision is the final ruling in the long-running case.
The pair were found guilty in 2009, then freed in 2011 after the convictions were overturned. Their convictions were reinstated by another court last year.
Ms Kercher was found dead in 2007 in a flat she shared with Ms Knox.
The couple had always maintained their innocence and the decision by the Court of Cassation puts an end to their long legal battle.
The reasoning behind the decision will be made public in 90 days.
Ms Knox has said that she feels “tremendously relieved” after the verdict.
“The knowledge of my innocence has given me strength in the darkest times of this ordeal,” she said in a statement.
Her family have said that they are “thrilled” with Friday’s court decision.
“We want to express our profound gratitude to all of those who have supported Amanda and our family,” they said.
Prof Greg Hampikian, a friend of the family who also worked on the DNA evidence for Ms Knox’s defence, told the BBC Radio 5 live that “everybody is very happy to see this finished, so they can get on with their lives.”
“She’s trying to start her life as a young woman, so hopefully this will be a really wonderful change and a new day for them and for Rafaele and his folks,” he said.
” I hope the Kerchers can find peace as well. It’s just been an up and down thing for everyone for so long.”
The lawyer for Ms Kercher’s family, Francesco Maresca, has expressed his disappointment with the verdict.
“I think that it’s a defeat for the Italian justice system,” he told the Associated Press news agency.
Ms Kercher’s mother has been quoted by the Press Association as saying that she is “surprised and very shocked” by the acquittals.
Twenty-one-year-old Ms Kercher was stabbed to death in the flat she shared with Ms Knox in Perugia, central Italy.
Her body was found under a duvet in her bedroom, which had been locked from the inside.
Days after the killing, Ms Knox and her Italian boyfriend at the time, Raffaelle Sollecito, were arrested.
They were convicted of murder in 2009 by a court in Perugia.
But in 2011, a jury cleared both defendants of the charge, after doubts were raised over the handling of DNA evidence.
A retrial was ordered after prosecutors argued that important evidence had been disregarded. In 2014, the guilty verdict was reinstated.
Another man, Rudy Hermann Guede, born in Ivory Coast, was also convicted in a separate trial and is serving a 16-year sentence for his role in the murder.