Italy's highest court on Thursday confirmed a slander conviction against U.S. defendant Amanda Knox for accusing an innocent man of murdering her British flatmate 17 years ago in a sensational case that polarized trial watchers on both sides of the Atlantic.

Amanda Knox, a former American exchange student, had been cleared of all other charges related to the death of her roommate in Italy 17 years ago.

An American who was convicted and later acquitted of the 2007 murder of her British housemate, Ms. Knox was found guilty of falsely accusing someone else of the crime.