Amanda Knox’s DNA was nowhere to be found in the bedroom in which Meredith Kercher was found stabbed to death, an Italian court heard on Monday.

On the first day of the American’s retrial, the court in Florence was told that there was ample DNA evidence from Rudy Guede, the Ivorian drifter who is serving a 16-year jail sentence after being convicted of the sexual assault and murder of Miss Kercher, 21.

‘‘How is it possible to find traces of Guede in enormous quantities but not a single trace of Amanda?’’ Giulia Bongiorno, representing Miss Knox’s ex-boyfriend, Raffaele Sollecito, 29, asked. ‘‘How is it possible that the only trace of Raffaele, which naturally we contest, was on the bra strap?’’

Tiny traces of Mr Sollecito’s DNA were found on a strap torn from Miss Kercher’s bra in the violent struggle that led to her death. But the strap was only discovered by forensic officers on the floor of the bedroom 47 days after the murder.