A mechanic who raped and strangled a 'beautiful and talented' city lawyer to death in her family home is facing at least 30 years behind bars.

Peter Kibisu, 23, killed Elizabeth Nnyanzi, 31, after being entrusted to stay at the £600,000 house in Harrow as a close family friend.

Kibisu was arrested the day after Elizabeth, who attended Cheltenham Ladies' College, was found dead in her bedroom on August 14 last year.

He pleaded guilty to the murder in November but continued to deny raping her until a hearing at the Old Bailey on Friday, January 8.

Kibisu unexpectedly admitted the rape charge and will now be sentenced on February 1.

Prosecutor Louise Oakley asked for the three-week delay to allow Elizabeth's father time to recover from illness and attend court.

She said: "The victim's father anticipates being in hospital for another two weeks. We would invite the court to allow him that time to attend as the family would all like to be here. The plea that was entered today wasn't anticipated."

Miss Oakley said that the starting point for sentencing for a sexually motivated murder was a life sentence with a minimum of 30 years before parole.

Kibisu showed no reaction as he was led down to the cells while Elizabeth's mother and two sisters sat in the well of court.

Elizabeth studied medicine at Imperial College before following in her father's footsteps to pursue a career in law, starting work at top international firm Herbert Smith Freehills in May last year.

She also worked for several charities including Freedom From Torture, a centre based in Finsbury Park with links to Amnesty International, and was a keen singer who had been asked to perform in an opera at the Royal Albert Hall.

Her mother Coreen is a food technology teacher at Nower Hill School, Harrow, and her father Joseph is a solicitor at a legal aid firm.

Detectives were called to her three-bedroom house, on Northumberland Road, shortly before 6pm on August 14 after police received reports of an unresponsive woman.

Paramedics from the London Ambulance Service raced to the scene, but Miss Nnyanzi was pronounced dead when they arrived.

A postmortem gave the cause of death as asphyxiation.

Following Kibisu's plea to murder in November, his barrister Courtney Griffiths said the crime had come as a "bolt from the blue".

Kibisu's address was given in court as the same Northumberland Road home, in Harrow, that Elizabeth and her family had lived in for 15 years.