Chef Mark Dixie (37), was said to have “taken advantage of the situation’’ after discovering the 18-year-old’s body in Croydon, south of London, the jury heard.

Brian Altman, prosecuting, warned the Old Bailey jury in London that graphic details would form a large part of the case because of the unusual nature of the defendant’s “desperate’’ defence. “It is born out of desperation for all too obvious reasons,’’ Altman told the court. “The Crown say Dixie killed that young girl.’’

Bowman was stabbed in the neck and abdomen at about 4 am in Blenheim Crescent, Croydon in September 2005, shortly after being dropped off close to her home by her boyfriend, the jurywas told. Sexual indignities were performed as the victim lay dying or was dead, Altman told the court, including sexual intercourse. The victim’s body was discovered by a neighbour when she looked out of her window about two hours later and saw a pair of legs sticking out from behind a skip in a house opposite.

“There she found, half on the drive and half on the pavement, the naked and bloodied body of Sally Anne,’’ the prosecution said. “She had been savagely and brutally killed. She had been stabbed several times in the neck and abdomen. “The knife passed through her abdomen and exited out the back. The motivation for the killing was sex for the killer’s own sexual gratification.’’  The prosecution went on to say that forensic tests showed DNA from semen found on the victim’s body came from the defendant.

His bloody fingerprint was also found on her left shoe. The chances of the DNA coming from anyone else were one billion to one, Altman said. Bite marks were also on her body, the prosecution said. “Dixie admits he had sex with her after her death but he denies he was the killer,’’ Altman said. “He says he was just in Blenheim Crescent by chance under the influence of drink and drugs and he chanced upon her body. “He says he took advantage of the situation and had sex with her when she was dead. That, we say astonishingly, is his defence,’’ said Altman. Bowman was a talented musician and had won a place at the British Record Industry Trust School.

At the time of her death she was working as a hairdresser and part-time model. Her dream was to become a top fashion model. Dixie, of no fixed address, had been celebrating his birthday on the night Bowman was killed. The trial continues.