DNA evidence in Amanda Knox trial 'may have been contaminated'

Some of the DNA traces used to convict American student Amanda Knox of murdering Briton Meredith Kercher may have been contaminated, independent experts say.

The review by two court- appointed experts was requested by the defence and has been eagerly awaited. Its conclusions could boost Knox's chances of overturning her conviction.

Knox was foundy guilty in 2009 of sexually assaulting and murdering Miss Kercher, from Coulsdon, Surrey - with whom she shared an apartment while both were exchange students in Perugia, Italy. She was sentenced to 26 years in prison.

Her co-defendant and ex-boyfriend Raffaele Sollecito was also convicted and sentenced to 25 years. Both have denied wrong-doing and are appealing.

Prosecutors maintained in the first trial that Knox's DNA was found on the handle of a kitchen knife they believe to be the murder weapon, and that Miss Kercher's DNA was found on the blade. They say Sollecito's DNA was found on the clasp of Miss Kercher's bra.

Those findings were disputed by the defence, and the appeals court granted an independent review.

The experts say in the report filed to the Perugia court yesterday that the genetic profile attributed to Miss Kercher is "unreliable" and cannot be attributed with certainty. They said results may have been contaminated on both the blade and bra clasp.

Regarding the blade, the experts said: "We believe that the technical tests are not reliable." The document said the tests did not conform to international standards and procedures.