ITALIAN lawyers have described Amanda Knox, the American student convicted of killing her British roommate, as a "she-devil" and a "witch" in an appeals court while calling her alleged victim a "beautiful girl in the prime of her life".

The court also saw gruesome photos of the semi-naked, bloodied body of Meredith Kercher on Monday as two lawyers made closing arguments at the appeals trial of Knox, 24, and Raffaele Sollecito, her co-defendant and former boyfriend.

Kercher, 21, was stabbed to death in the apartment she shared with Knox. Knox and Sollecito were convicted of sexually assaulting and murdering her. Knox was sentenced to 26 years, Sollecito, an Italian, to 25. They deny wrongdoing and have appealed their convictions, which were issued by a lower court in 2009.

"Who is Amanda Knox?" said attorney Carlo Pacelli. "Is she the mild-looking, fresh-faced person you see here, or the one devoted to lust, drugs and alcohol that emerges from the court documents?"

Pacelli represents Diya "Patrick" Lumumba, the owner of a bar in Perugia who, shortly after the 2007 murder, was unjustly accused by Knox of being the murderer. He was briefly jailed and then cleared.

Pacelli maintained that a double soul coexists in the American.

"Both a (saint) and a demonic, satanic, diabolical she-devil, which leads her toward borderline behaviour. This was the Amanda of November 1 2007," the night of Kercher's murder, Pacelli said.

Knox at the time of the crime "was an explosive mix of drugs, sex and alcohol," he insisted. "She is a spell-casting witch, a virtuoso of deceit."