THE WOMAN who fatally stabbed a 23-year-old man in her Banbury home feared she had "ruined" her life, a court was told.

Natasha Capell denies murdering Kyle Byfield at her Jubilee Court home on April 16.

But the mother-of-one admitted one count of manslaughter during the first day of the trial on Monday.

Jurors at Oxford Crown Court were told on Tuesday[oct6] Mr Byfield died of a stab wound to the chest.

They heard the victim was with best friend Jake Orwa and Capell at her home when she stabbed him with a 20cm blade.

Prosecutor Alan Blake told the court Capell disposed of the knife in a newspaper storage box while paramedics, who arrived at about 7.30am, were fighting to save Mr Byfield.

Police officer Lucy McDonagh yesterday[oct9] told jurors she arrived at Jubilee Court at about 8.10am and took Capell to her mother's Bretch Hill home to see her young daughter who was staying there.

The officer said the defendant was "sobbing" to her mother at the house and heard her say "I've ruined my life".

PC McDonagh told the court she later arrested Capell, who said "nothing even happened" when she was cautioned in the police vehicle.

Defence barrister Adrian Redgrave put it to the officer that Capell was "completely distressed" and had difficulty breathing after later finding out Mr Byfield had died.

PC McDonagh replied: "Yes. She looked physically in shock at the suggestion that he had died."

Jake Orwa's brother Danielle, who was friends with Capell, told jurors her brother came to her home and told her about the stabbing shortly after leaving the scene.

The mother-of-one said Mr Orwa was "hysterically crying" and said he was going to kill himself after seeing Capell stab his best friend.

She added: "I think Natasha panicked when she realised what had happened. She asked him [Mr Orwa] to hide the weapon but he said no."

The trial continues.