Amanda Knox takes the stand

Amanda Knox, the 21-year-old exchange student from Seattle accused of killing her British flatmate Meredith Kercher in a would-be orgy that ended in tragedy, is expected to give evidence today at her trial in the Umbrian capital, Perugia.

"She's a bit nervous about going on to the stand," her father, Kurt Knox, told the CBS Early Show, "but she's also quite confident in what she has to say and that the truth will come out during her testimony."

The case against 21-year-old Knox is that on the night of November 1, 2007, along with her Italian boyfriend, Raffaele Sollecito, 25, and another man, Rudy Hermann Guede, she engaged Kercher, against her will, in a sex game.

Knox, say her Italian prosecutors, held a kitchen knife to Meredith's throat while Sollecito held the English girl's shoulders and Guede tried to sexually assault her. At which point, they claim, Knox stabbed Kercher in the throat.

Police found Knox's DNA on the handle of the knife they claim was used in the murder, and traces of Kercher's DNA on the blade.

Guede, an Ivory Coast national, has already been sentenced to 30 years in jail in a separate, fast-track trial. Knox and Sollecito went on trial for murder in January, but with the court sitting only two days a week, the verdict cannot be expected until later this summer.

Since she was taken into custody in 2007, Knox has become a celebrity in the Italian media, where much is made of her angelic looks and her nickname 'Foxy Knoxy'. The fact that she inherited the moniker for her skills on the football pitch and not her sexual appetite, is long forgotten.

However, Knox's openness about her sexuality has not always served her cause: as the Independent on Sunday reported last week, court reporters did a double-take when Knox made a statement that offered far more detail than was necessary.

Responding to a claim made in court that she kept condoms and a sex toy in a transparent beauty case, she said: "The vibrator. It exists. But it was just a joke, a gift from a friend before I came to Italy. It is a tiny pink rabbit about 15 centimetres."

There have been reports that Knox has been pressured into making various self-incriminating and conflicting statements, including an initial accusation that it was a Congolese bar-owner, Patrick Lumumba, who killed Kercher while Knox hid in another room blocking her ears to the English girl's screams. Lumumba was cleared after being detained for two weeks, and Knox retracted the statement.

Knox's stepfather, Chris Mellas, claimed in March that she had been repeatedly beaten by Italian police during all-night interrogations.

Today, the American finally gets her chance to tell her story in open court. Kurt Knox told CBS that his daughter has been learning Italian during her months in jail and aims to speak mainly in Italian during her testimony. ·