Flatmate 'admits involvement' in British woman's murder as two others are held

The investigation of the murder of an English exchange student took a dramatic turn yesterday when her 20-year-old American flatmate broke down during questioning and confessed to involvement in the killing, Italian police said.

Meredith Kercher, 21, who was found dead in Perugia last week, was killed while fighting off a sex attack, according to detectives. Three people have been arrested – Miss Kercher's US housemate Amanda Knox, 20, Miss Knox's Italian boyfriend Raffaele Sollecito, 24, and Patrick Diya Lumumba, a 37-year-old Congolese man who runs a restaurant in the city centre.

All three were taken from their homes in early morning raids. Officers intend to charge them with participating in an act of sexual violence as well as manslaughter.

In a brief press conference, the Perugia police chief Arturo de Felice said the arrests followed intensive detective work since Miss Kercher, of Coulsdon, Surrey, was found dead in her apartment on Friday. "All three participated in this crime. The motive was sexual and the victim rebelled," he said, adding: "The motive appears to have been a sexual attack. However, Miss Kercher was the victim and that's all. She was morally innocent of what occurred."

When asked by journalists whether one of the three people being questioned had confessed to the crime, police said this was a "valid hypothesis". Post-mortem examinations revealed that Miss Kercher had neither alcohol nor drugs in her system at the time of death. The pathologist said there was no evidence to indicate she was raped but bruises and lesions on her body were consistent with a struggle.

The body of Miss Kercher, who was in Perugia for a year studying political science and Italian as part of her BA course at Leeds University, was discovered in a pool of blood in her bedroom in the first-floor flat near the city centre that she shared with Ms Knox and two Italian girls. She was naked except for her blouse, which was raised above her chest, and she had been killed by a slashing wound to her neck, apparently from a penknife or kitchen knife. Police said early in the inquiry that she probably knew her killer or killers because she apparently let them into the flat willingly. Nothing was removed from the property except her two mobile phones, which were found in a nearby park.

Now it appears that Miss Kercher, known as "Mez" to her friends, was the victim of a bizarre and sadistic attack by people she had reason to trust, although Mr de Felice gave no details of what detectives believe actually occurred on Friday night.

Miss Knox made no attempt to flee before her arrest yesterday. She was photographed talking casually to police in the garden of the home she shared with Miss Kercher. Italian news reports said last night that Miss Knox distributed flyers for Mr Lumumba's restaurant – and that Miss Kercher was hoping to be hired for the same work.

Mr Sollecito, from Bari in southern Italy, said over the weekend that he and Miss Knox were the first to "discover" Miss Kercher's body. "It's something I never hope to see again," he added. "There was blood everywhere and I couldn't take it all in. My girlfriend was her flatmate and she was crying and screaming, 'How could anyone do this?'We went into [Miss Knox's] bedroom and it had been ransacked, like someone had been looking for something. But when we tried Meredith's room, the door was locked. She never normally locked her bedroom door, and that really made us frightened. I tried to knock it down. I thought maybe she was ill. I made a dent but I wasn't strong enough on my own so I called the police."

Police arrived and broke down the door. "I couldn't believe what I was seeing," Mr Sollecito said. "It was hard to tell it was Meredith at first but Amanda started crying and screaming. I dragged her away because I did not want her to see it, it was so horrible." Mr Sollecito describes himself in his internet blog as "honest, peaceful, sweet but sometimes completely crazy". He adds that his favourite drama is Hamlet, his favourite sport is kick-boxing and that Jamaica is his preferred holiday destination.

According to Italian media reports, contradictions in Miss Knox's evidence gave police the breakthrough which led to the arrests, but the roles played by the three suspects remain to be clarified. One news agency said Miss Knox worked in the restaurant run by Mr Lumumba, who has lived in Perugia for more than a decade and is a well-known figure. The manager of another Perugia restaurant said: "I have known Patrick for 10 years. He is a nice, cultured guy, he has a Polish girlfriend and a baby a little over a year old."

He said that Mr Lumumba came from the upper echelons of Congolese society. His mother is the proprietor of a newspaper, while his grandfather was Patrice Lumumba, the first democratically elected president of Congo, who was murdered a couple of months after coming to power in 1961.