Prosecutors investigating the murder of Meredith Kercher believe that the knife found in the flat of one of the suspects was taken into Ms Kercher’s bedroom with the intent to kill or harm.

Detectives are to press for charges of premeditated murder. Two Italian students who shared the home of Ms Kercher testified “categorically” yesterday that the knife had never been part of their cottage kitchen. Detectives say that it must therefore have been brought in “with intent to kill or inflict harm”.

The 8in (20cm), black-handled kitchen knife was found in the flat of Raffaele Sollecito, 23. DNA traces of his American girlfriend, Amanda Knox, 20, and Ms Kercher, with whom she also shared a cottage, were found on the blade.

No traces of blood were found on the kitchen knife. But investigators said that “biological traces” remained, suggesting blood had been washed from the blade.

New witness 'saw Meredith suspects together'

Amanda Knox, Raffaele Sollecito and Rudy Guede were see at the house in Perugia where the American student died

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• Murder in Perugia

BACKGROUND

• Meredith Kercher: Q&A

• New DNA not from Meredith suspects

• Timings crucial to Kercher murder investigation

Related Links

• Meredith brother codemns media for dead sister pic

• DNA on knife links Knox and Meredith

• US suspect in Meredith case 'turning to religion'

Giacinto Profazio, head of the Perugia police flying squad, said that DNA from both Ms Knox and Mr Sollecito had also been found on rags apparently used to clean the scene of the crime.

Police said that the cleaning lady at Mr Sollecito’s flat had testified that two empty containers of bleach found there had not been bought or used by her. The investigators’ supposition is that the bleach was used to clean the kitchen knife, and Mr Sollecito’s trainers, which match bloody footprints at the cottage, but on which no traces of either blood or DNA were found.

Yesterday Ms Kercher’s brother condemned parts of the media for publishing a picture of his sister as she lay dead on her bedroom floor. Lyle Kercher, 35, told La Stampa: “All I know is that when I saw they had published the photograph of my sister lying on the floor of her bedroom, I thought I was dreaming, I thought that this can’t be true. It is intolerable, absolutely intolerable. Allow us the right to suffer in peace.” Describing his sister as a “marvellous girl”, he said that the family had found it hard “not only because there still isn’t anyone guilty, but sometimes it almost seems as if there wasn’t even a crime.

“My family trusts the magistrates in Perugia. Totally. Let’s let them do their work.” He added that if those responsible for his sister’s death were not brought to justice it would be “like killing Mez a second time”.

Ms Kercher was found semi-naked with her throat cut two weeks ago. Ms Knox, Mr Sollecito and Diya “Patrick” Lumumba, 37, a Congolese bar owner and reggae musician, were arrested four days later and are being held on suspicion of murder and sexual violence. Police say that all three subjected Ms Kercher to a sexual attack before killing her.

It is unclear, however, whether all three still face murder charges. The overwhelming view among the people of Perugia is that Mr Lumumba, a popular figure in the town and a resident since 1988, has been framed. A march through the city’s streets demanding Mr Lumumba’s release will be staged tomorrow.

Several witnesses have testified that Mr Lumumba was behind the till and serving drinks at his bar, Le Chic, on the evening of the murder. However, none can swear that he was there the whole time, and police say that a signal trace of his mobile phone was recorded near the cottage between 8pm and 9pm. Giuseppe Sereni, his lawyer, said that police had so far found no traces of Mr Lumumba’s DNA at the cottage, “for a simple reason — he was never there”.

Police said that the search for a “fourth person” was continuing, following the discovery of faeces in the cottage lavatory and fingerprints on Ms Kercher’s bloodsoaked pillow which were not those of any of the three suspects. “The fourth person is more than a hypothesis,” one investigator told The Times.

Mr Sollecito’s lawyers yesterday lodged an appeal for his release, saying the leak to the media of the news that the DNA of Ms Kercher and Ms Knox was on the knife found in his flat “does not alter his position”.

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