Student David Quartey has denied being responsible for the frenzied stabbing of his guardian Dr Victoria Anyetei as she sat in her car outside her Dartford home.

In an emotional outburst in the witness box, he told the jury at Maidstone Crown Court: "I didn't kill her. I have been accused of killing someone I loved."

The prosecution allege that the 22-year-old stabbed Dr Anyetei 57 times while under pressure from failing college examinations as he worked towards a law degree.

Prosecutor Anthony Haycroft said Quartey had about two hours to dispose of vital evidence on the morning of the killing - August 14 last year.

The son of a High Court judge in Ghana, Quartey said he had a "mother and son relationship" with the 56-year-old consultant paediatrician while living at her house in Teynham Road. He and her son Andrew Thompson were like brothers.

"She really cared what was going on in my life," he said. "I respected her. I was never rude to her. I either called her mum or doc."

Quartey, now of Humber Road, Dartford, denies murder.

The trial continues.