The mother and grandmother of a teenager who was allowed to “rot to death” on an inflatable mattress have been convicted of his manslaughter.

Jordan Burling was said to have resembled the victim of a Second World War death camp when paramedics found him lying lifelessly on the makeshift bed, weighing just 6st.

As a result of barely moving for weeks, he was covered in bed sores, and was wearing a soiled nappy when he died from acute bronchopneumonia at his home in the Farnley area of Leeds in June 2016.

On Tuesday, a jury at Leeds Crown Court unanimously convicted his 45-year-old mother Dawn Cranston of manslaughter, as well as his grandmother, Denise Cranston, 70.

Mr Burling’s 25-year-old sister, Abigail Burling, was found not guilty of manslaughter, but guilty of an alternative charge of causing or allowing the death of a vulnerable person.

During the five-week trial, prosecutor Nicholas Lumley QC described the extent of the neglect that the two relatives showed towards the teenager, telling jurors: “Jordan had been allowed to decay, to rot to death, by those closest to him, over a period of, at least, several weeks.”

The court was also told that Mr Burling was “invisible to the authorities” and that, despite his troubled life, had only minimal contact with stage agencies, including the education system.

The court heard that he attended his local primary school, where he soiled himself and defecated on the floor. Teachers noted he had head lice and his teeth were in a very poor state.

Soon after he went to Farnley Park High School, his mother wrote to the council telling them that he was going to be educated at home. He was “home-schooled” from the age of 12, jurors were told.

Following the verdicts, Gerry Wareham, from the Crown Prosecution Service (CPS) Yorkshire and Humberside, said Mr Burling’s death was “one of the most shocking cases” they had ever dealt with.

Dawn and Denise Cranston will be sentenced for the manslaughter of 18-year-old Jordan Burling on Thursday morning at Leeds Crown Court.

Mr Burling’s sister, Abigail Burling, will be sentenced at the same time, after being found guilty of causing or allowing the death of a vulnerable person. They were granted bail until then.