ROME - AN AMERICAN student known as 'Foxy Knoxy' goes on trial on Friday for her alleged role in the presumed sex-murder of her British housemate in the sleepy Italian university town of Perugia.

Amanda Knox, from Seattle, Washington, has been held awaiting trial since a few days after British exchange student Meredith Kercher, aged 22, was found dead semi-nude in her bedroom with her throat slit on Nov 2, 2007.

Knox's then boyfriend Raffaele Sollecito is also implicated in an alleged scenario in which Ms Kercher refused to take part in a sex game following an afternoon Knox allegedly spent smoking hash with Sollecito.

A third defendant, 20-year-old Ivorian Rudy Guede, has already been convicted and sentenced to 30 years behind bars for his role in the murder.

While claiming innocence, he opted for a 'fast-track' trial in exchange for clemency.

Guede, who fled the scene - and Italy - was arrested several days after the murder in Germany, and extradited.

Ms Kercher, a student from Leeds University, was studying in Perugia as part of the Erasmus exchange programme.

Her murder, which occurred on the night of All Saints Day, just after many students in Perugia celebrated Halloween, sparked lurid headlines in Britain and the United States.

Journalists quickly spotted 21-year-old Knox's MySpace page in which she called herself 'Foxy Knoxy,' as well as a YouTube appearance by Guede in which he said he was a vampire who would 'suck your blood.'

Guede has said he met Ms Kercher on Halloween, and that they set a date for the night of the murder.

Knox, too, showed up on YouTube looking drunk, while her MySpace page displayed a picture of her laughing while handling a machine-gun.

Sollecito posted a photo of himself wearing something like a hazardous materials suit, brandishing a meat cleaver and holding a container of pink liquid in his other hand.

Knox and Kercher shared a house with two Italian women who were away for the holiday weekend at the time of the murder.

Prosecutors say Knox stabbed Ms Kercher to death while Sollecito and Guede restrained her and the latter tried to rape her after she refused to take part in a drugs-inspired sex game linked to Halloween.

Luciano Ghirga, a lawyer for Knox, said he would 'radically contest' the prosecution's murder scenario, noting that 14 traces were found of a person other than any of the accused.

Sollecito says the murder was the result of a bungled robbery attempt by Guede.

Meanwhile, Ms Kercher's family is seeking 30 million euros (S$60 million) from her alleged killers. -- AFP