Two teenagers have been jailed for killing a suspected paedophile.

A 15-year-old girl from Streatham was jailed for six years for manslaughter and her sister’s boyfriend – a 15-year-old from Clapham – got nine years for murder, at the Old Bailey today.

The pair killed Robert Daley, 45, in his kitchen just an hour after they discovered he would not face prosecution for a string of alleged sexual assaults. He was stabbed five times, including twice through his heart.

During her trial the girl claimed Mr Daley abused her from the age of 12 as well as her sister.

Police had investigated claims of sex attacks on her 16-year-old sister and another woman but had dropped the case because of a lack of evidence.

The two killers, 14 at the time of the attack, went to Mr Daley’s flat in Ferndale Road, Brixton, shortly before 6pm on April 23 this year, after the elder sister telephoned them to say the police had dropped the case.

Mr Daley had rung to tell her the news.

During the trial, the boy admitted stabbing Mr Daley. But both he and the girl told the court it was after Mr Daley abused the girl in front of him.

He said he grabbed a knife from the sink and stabbed Mr Daley had gone to grab a knife as he tried to save her.

The pair cannot be named.