A woman who murdered a vulnerable teenager and continued collecting her benefits payments for almost 18 years has died behind bars.

Avril Jones, 66, a prisoner at HMP Stirling, died in custody on 8 November.

Jones and her partner Edward Cairney, 82, were convicted of murdering Margaret Fleming, who was last seen alive aged 19 at a family gathering in December 1999.

Margaret had learning difficulties and stayed with Cairney and Jones inside a squalid cottage in Inverkip, Inverclyde, after they became her "carers" following her father's death.

The pair murdered Margaret between December 1999 and January 2000.

Jones went on to claim £182,000 in benefits while the pair staged an elaborate cover-up, which police described as "greedy" and "fantastical".

Margaret was reported missing in 2016, and her body has never been found.

The pair were convicted at the High Court in Glasgow in 2019 and detectives issued an appeal to Cairney and Jones to reveal where Margaret’s remains were, on what should have been her 39th birthday.

“Every death, whether in prison custody or in our communities, is a tragedy for all those who knew and supported the individual,” a Scottish Prison Service spokesperson said.

“Following the death of someone in our care, Police Scotland are advised and the matter reported to the procurator fiscal. Fatal accident inquiries are held in due course.”

Police launched an investigation after it became apparent in October 2016 that Ms Fleming was missing.

Routine social services inquiries were said to have sparked concerns over her whereabouts.

Her carers were arrested in October 2017.

During the trial of Jones and Cairney, which began in April 2019, Ms Fleming was described by prosecutors as a “friendless and lonely” young woman who had significant difficulties.

She went to live at the Seacroft home of the accused following the death of her father when she was a teenager, after those closest to her “didn’t want her”.

By October 1999, various benefits for Ms Fleming flowed into the household.

The Crown suggested it was “tempting” for the couple to have the money but not the “inconvenience” of looking after her.

How and exactly when Ms Fleming died may never be fully known. It remains, as the defence highlighted, a case without a body and without a crime scene.

Holding them jointly responsible for the death, the Crown claimed the couple “literally got away with murder for 16 years”.