Edward Cairney, 82, died at HMP Edinburgh on Sunday, the Scottish Prison Service (SPS) has confirmed.

The pensioner had been sentenced to life alongside partner Avril Jones for the murder of Margaret Fleming.

Ms Fleming, 19, who had learning difficulties, was last seen around December 1999 but it did not become apparent she was missing until October 2016.

Cairney and Jones, her supposed carers, were arrested a year later.

In 2019, the pair were found guilty of murder and perverting the course of justice and were sentenced to life imprisonment with a minimum term of 14 years.

Jones was also convicted of fraudulently claiming £182,000 in benefits by pretending Ms Fleming was still alive.

Ms Fleming's body has never been found despite painstaking searches of their home in Inverkip, Inverclyde.

During Cairney and Jones' sentencing, judge Lord Matthews said: "Only you two know where her remains are.

"That remains a source of immense grief as far as her mother is concerned.

"It seems obvious that the motive for the murder and cover up was financial."

A court heard Ms Fleming had moved in with Cairney and Jones when she was a teenager following the death of her father after those closest to her reportedly "didn't want her".

By October 1999, the household - said to have financial troubles - was collecting her benefits.

Prosecutors alleged that Ms Fleming was murdered at some point between December 1999 and January 2000.

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

Both Cairney and Jones were said to have "literally got away with murder for 16 years" and devised an "elaborate scheme" to conceal her disappearance.

As police zoned in on the couple, their fabricated stories to explain Ms Fleming's absence became increasingly "farcical" as they tried to reconcile claims she was both working as a gangmaster and capable of travelling overseas, and that she was someone with major difficulties requiring a number of benefits.

Following their conviction, Detective Superintendent Paul Livingstone said on what would have been Ms Fleming's birthday: "It's very important that she is given the funeral she deserves and for her family to be able to pay their respects to her.

"I would say again to Eddie Cairney and Avril Jones - your lies have caught up with you, so now do the decent thing and let Margaret's family know what has happened to her."

On Tuesday, the SPS said: "Edward Cairney, 82, a prisoner at HMP Edinburgh has died on 15 October 2023.

"He was convicted at Glasgow High Court in 2019.

"Police Scotland have been advised and the matter reported to the Procurator Fiscal.

"A Fatal Accident Inquiry will be held in due course."