A crime expert is hoping a new documentary about Margaret Fleming’s murder will put pressure on her killers to reveal the location of her body.

The case is featured in the first episode of TV series Murder At My Door, on the the Crime+Investigation channel.

Carers Edward Cairney, 78, and Avril Jones, 60, were jailed for at least 14 years each in 2019 for Margaret’s killing, which took place between December 1999 and January 2000, when she was just 19.

Jones pocketed £182,000 in benefits after the pair pretended Margaret was alive for 17 years. Despite the convictions, the pair have refused to disclose what happened to her body.

Avril Jones who was found guilty of the murder of Margaret Fleming

Former detective superintendent David Swindle, 65, hopes the programme will lead to Cairney and Jones revealing where Margaret’s remains are hidden.

He said: “The way they have treated that woman is terrible, spine-chilling stuff. Margaret and her family deserve justice.

"She was a vulnerable person who trusted these people. They not only took her money but killed her. I would appeal to Cairney, in particular, ‘What have you done with Margaret? Where is she?’”

Testimony from Jones’s brother Richard was used to pinpoint the last independent sighting of Margaret. Three weeks later, Jones told her mother Florence that Margaret ran off with a traveller.

Cairney and Jones, who had no previous convictions, embarked on a cover-up which involved bogus letters and erasing all trace of Margaret from the cottage in Inverkip, Renfrewshire, where she had lived for about two years.

Police were alerted in October 2016 after Jones filled in a PIP application. In it she wrote that Margaret “needs constant care”, had self-harmed and was “caught eating out of a dog bowl”.

Edward Cairney who was found guilty of the murder of Margaret Fleming

A social worker rang Jones to offer help and was told Margaret had not been to the doctor, despite picking a hole in her head.

Police Scotland then launched a missing persons’ investigation.

Swindle, who now runs a multi-lingual crime solutions team helping the families of Brits killed abroad, added: “There’s no doubt they killed Margaret.

"Cairney knows where Margaret’s body is and is enjoying the control of holding that back.

“He’s either really thick, really stupid or enjoying the glory of withholding that information.”

Murder At My Door with Kym Marsh returns on Monday, February 1, on Crime+ Investivigation.