The student lovers who murdered Meredith Kercher have suffered a blow to their appeals, after Italian judges announced there were no holes or inconsistencies in the original evidence.

Amanda Knox and Rafaelle Sollecito were found guilty in December of killing Miss Kercher, who was sharing a house with Knox at the time while on a year abroad in Perugia, Italy.

The case judges today published a 427-page opinion document explaining their reasons for convicting the pair, which calls the death a result of “purely random circumstances”.

It explains Knox and Sollecito staged a fake break-in to make it look like Miss Kercher was killed by an intruder, adding the murder was committed “without planning, without any animosity or grudge against the victim”.

The prosecution originally claimed the 21-year-old student died during a sex party which went wrong, before suggesting she had fallen out with Knox over the latter's hygiene habits and interest in men.

The judges added Miss Kercher’s killers showed “a sort of regret for what they had done” by covering her body after the murder.

Knox was jailed for 26 years and Sollecito for 25 years for the killing, while small-time drug dealer Rudy Guede was imprisoned for 30 years for his part in the murder during an earlier hearing.