Knox, 22, and Raffaele Sollecito, 25, killed Kercher in an attack which ended with Sollecito taunting Kercher with one knife while Knox plunged another into her throat, the court heard during the trial.

Kercher, 21, from Coulsdon, Surrey, was found with a deep knife wound in the throat on the floor of her bedroom in the flat she shared with Knox and two young Italian women. She was a student at Leeds University and was spending a year at Perugia’s university for foreigners when she was found murdered on November 2, 2007.

Knox, who came into the courtroom weeping and shaking, appeared not to react immediately as the sentences were read out, but then broke down and buried herself in the shoulder of her senior lawyer Luciano Ghirga. She was led from the court by police and her sobbing could be heard from the corridor that leads away from the vaulted underground court in which the trial has been heard. Her younger sister Deanna, 20, wept. Sollecito, who had been less composed than his former girlfriend during the trial, sat rigidly, staring ahead as the colour drained from his face. His stepmother was seized by a panic attack and appeared to be hyperventilating.

Knox was sentenced to 26 years in prison while Sollecito was sentenced to 25 years. Knox was also found guilty of several other offences, including criminal slander for pointing the finger of guilt at Diya “Patrick” Lumumba, 38, who ran a local bar. He later proved to have an alibi and was released after initially being arrested in connection with the murder.

In tears

Knox’s family left court in tears and fought their way through the dense crowd. Asked if he would fight on, Curt Knox, the American student’s father, replied: “Hell, yes.”

Kercher’s family lawyer Francesco Maresca said they were satisfied with the verdict. He said: “They got the justice they were expecting. We got what we were hoping for.”

The verdict put an end, though perhaps only a temporary one, to a case that has baffled and divided amateur detectives on both sides of the Atlantic and turned a probing light on the Italian legal system. Knox, a student at the University of Washington, and her boyfriend were sent for trial despite the fact that a third person had been convicted of the killing before their indictment. Rudy Guede, a drifter born in the Ivory Coast, was sentenced to 30 years last year after a fast-track trial. He is appealing against his conviction.

The verdict will almost certainly prompt another appeal as Knox and Sollecito, a computer science graduate, try to establish their innocence in a higher court.