Amanda Knox's father has revealed that he has mortgaged his house and lost everything he owns to defend his daughter.

Curt Knox's daughter, 21, and her ex-boyfriend Raffaele Sollecito, 25, are jointly accused in the murder of 21-year-old Meredith Kercher, a British student who was found semi-naked with her throat cut in the bedroom of the Perugia house she shared with Knox.

Knox told Italian TV that the family has spent more than $975,000 defending his daughter.

"This is costing us a lot of money," he told talk show Matrix. "We are approaching seven digits. We have mortgaged everything, our retirement has gone, everything has gone. We will do all that it takes to get Amanda freed and we will worry about the finances later,'' he added, close to tears.

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The Knox family have hired a PR consultant, two lawyers and paid for independent examinations of DNA evidence against their daughter.

But Knox said the cost to prove her innocence is worth it. He pointed to the fact that Amanda had remained in Italy after the murder and not fled, unlike third defendant Rudy Guede, who was handed a 30-year sentence in October.

''When this happened, we asked her if she wanted to come home but she said she wanted to stay and help the police catch the person responsible for this terrible crime," he said.

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