A couple who killed a drug addict outside a flat in Hendon after he stole their supply of cocaine have been found guilty of his murder.

At Southwark Crown Court on Friday, Kelly Chaffe, 20, of Connaught Road, Barnet, and her boyfriend Christopher Richards, 30, of Park Mansions, Vivian Avenue, Hendon, were convicted of murdering 42-year-old Brian McIlvaney.

The court heard how the pair tracked down Mr McIlvaney, and told his teenage step-daughter, 'Your dad is going to die today', before plunging a knife into his back.

When the jury announced its verdict the pair burst into tears before Chaffe turned to her boyfriend and told him: "This is all your fault."

On August 27 last year, they traced Mr McIlvaney to an address in Cricklewood after he took Richards' drugs. When the pair arrived at the house they found Mr McIlvaney's 16-year-old step-daughter alone in the house.

She told the court: "A girl barged in and pushed me out of the way. She was shouting: 'Where is he, where is he?' really aggressively and kicking things. She said she was going to kill him or that he was going to die today and she left."

Chaffe and Richards waited for their victim in a narrow entrance off Studio Mews, in Glebe Crescent, Hendon, where Mr McIlvaney was visiting a friend. When Mr McIlvaney appeared outside a flat they attacked him, repeatedly punching and kicking him, before Chaffe stabbed him. Mr McIlvaney, who had previously lived in Australia with his wife, was left to die on the ground outside the flats.

Although the murder weapon has never been found, pathologists told the court the fatal stab wound could have been caused by a paper knife.

The couple, who were also found guilty of conspiring to commit grievous bodily harm on the same date, will be sentenced on July 21.

A third defendant, Jose Marques, 39, of Cypress Road, Cricklewood, who was alleged to have pointed out where the victim lived, was cleared of conspiring to commit GBH.