10:12pm UK, Wednesday June 29, 2011

Nick Pisa, in Rome

Convicted killer Amanda Knox’s hopes of being freed on appeal have risen dramatically after it emerged crucial DNA evidence may have been contaminated.

An independent witness report has ruled that results from DNA tests in the initial trial “may have been contaminated” and that “international procedures were not followed”.

Knox, 23, is serving 26 years for the brutal knife murder of British student Meredith Kercher, 21.

Miss Kercher was found semi-naked and with her throat slit in her bedroom in the house the two women shared.

Knox was convicted 18 months ago along with her ex-boyfriend Raffaele Sollecito, 27, who was jailed for 25 years. Both deny any involvement.

British student Meredith Kercher was killed in Italy in 2007

In recent months there has been growing unease about the strength of the verdicts.

Key to the case was hotly-disputed DNA evidence – the original trial heard that genetic material from Ms Kercher was found on the blade of a 30cm kitchen knife recovered from Sollecito’s flat.

The DNA of Knox was also found on the handle of the knife, the court heard.

At the time, both legal teams argued that the results were so low they should not have been admitted as evidence.

There was also question marks over contamination of evidence, in particular, a bloodied bra clasp belonging to Ms Kercher on which DNA from Sollecito was found, had been lost for “six weeks” before being recovered.

A request for a review was overturned by the trial judge.

But in January, appeal court judge Claudio Pratillo Hellman appointed two independent witnesses Carla Vecchiotti and Stefano Conti from Rome’s La Sapienza University to look at the evidence.

In their report, which was filed at a Perugia court hearing Knox’s appeal on Wednesday, they ruled it was “not certain that DNA from Meredith was on the knife”.

It also claimed that “contamination on the bra clasp could not be excluded”.

They added: “It cannot be excluded that the results obtained may have been derived from ambient contamination or during the handling of the evidence.”

Sollecito, the ex-boyfriend of Knox, was also convicted over Ms Kercher’s death

It went on: “With regard to the bra clasp, we believe that the results are not reliable because scientific elements do not exist which can rule out the possibility of contamination from elsewhere.”

The experts also stressed that “international standards of searching for and gathering evidence were not followed with regard to the knife and the bra clasp”.

With regard to the knife, they said the DNA provided a “low copy number”.

They added: “Due care and caution should then have been used in attributing the result to Meredith Kercher, although we agree with the findings that the genetic evidence on the handle is Knox’s.”

Professor Stefano Conti, one of the experts involved, said: “It was a complex job and we examined a huge amount of data and are happy with the conclusions we have reached.”

Knox’s lawyer Carlo Dalla Vedova said: “This news just confirms what we have always said from the beginning.

“I have not had a chance to speak with her yet but I’m sure she will be delighted, as are her family. It is very good news for her and it is what we are placing all our emphasis on.”

The Kercher family lawyer Francesco Maresca said: “I’m astonished by the findings of these experts.

“We all know the high professional standards of the police forensic teams who conducted the initial investigation.

“These two are inexperienced experts, I cannot accept their findings and we will attempt to clear up their mistakes in court. We remain convinced of Knox and Sollecito’s guilt.”

The findings will be officially discussed in court next month when the case resumes but a verdict is unlikely before the autumn.

Ms Kercher, from Coulsdon, Surrey, was in Perugia as part of her Leeds University degree and had only been in Italy for two months before she was murdered in November 2007.