A mother who joined in a fatal attack on her 13-year-old daughter’s boyfriend after he posted topless pictures of the girl on the internet will serve less than three years in jail.

Gedu Bibi, 47, lured 21 year-old hospital worker Sumon Miah to her home after being shown the photos of Shuhina Khanam.

Once there he was hit over the with a chair leg and he fell into a coma from which he never recovered. Mr Miah died nine days later from brain damage on October 17, 2006.

The attacker who inflicted the fatal blow has never been found - though Bibi’s defence team have pointed the finger at her husband Angur Miah, who fled to Bangladesh two weeks before her trial began.

Bibi got her teenage daughter to tell police she had hit the victim in self defence after he turned up with a knife. Her 12 year-old son Fhalak also backed up the story.

Detectives shut down their investigation in 2008 but fresh information emerged two years later which led to Bibi and her former lover, 48-year-old cafe owner Lilu Miah, being charged with murder.

After a trial at the Old Bailey, jurors cleared Bibi of murder but convicted her of manslaughter and perverting the course of justice.

Judge Gerald Gordon gave her a seven-year jail term - but she will be released on licence in less than three years, having already spent 324 days behind bars on remand.

Judge Gordon told her: “Whoever struck that fatal blow, it wasn’t you.”

“However, on the jury’s verdict you were involved and you were thereafter involved, probably with one or more other adults,

Lilu Miah, 48, was cleared of both murder and manslaughter after claiming he was at the barbers at the time of the killing.

He was convicted of perverting the course of justice for telling police he had been at his cafe in South Woodford, at the time of the killing.

But Judge Gordon said he was powerless to impose an additional jail term on Miah, who was sent to prison for a minimum of ten years in March 2010 for holding his girlfriend hostage above his cafe and repeatedly raping her.

Bibi, of Priory Road, and Lilu Miah, of no fixed address, both denied murder.