A woman and her female partner have been convicted of the “horrific” killing of her son and then attempting to blame it on a seven-year-old boy.

Thirty-one year-old Rachel Trelfa, or Fee, and her civil partner Nyomi Fee, 29, subjected two-year-old Liam Fee to a prolonged period of abuse.

They showed little emotion as the two verdicts were returned, while Liam’s father Joseph Johnson was in tears as he left the High Court in Livingston.

The toddler was found with more than 30 injuries to his body, the fatal blow being a blow to the abdomen which ruptured his heart.

Rachael Fee and her civil partner Nyomi Fee (right) killers of liam fee

Trelfa and Fee also abused two other boys in their care

The court heard that the fatal injuries were similar to those seen in car crash victims.

To cover up their crime, the pair convinced a seven-year-old boy in their care that he was the killer.

They told him he had strangled Liam and placed his hand inside the dead boy’s mouth to ensure DNA transfer, in an apparent effort to bolster a forensic case against the child.

It was only when the boy was interviewed by police and social workers that they began to realise the evidence against the boy did not stack up.

Having begun the interview process believing that he had committed murder, the boy was reassured that he was not, in fact, the killer.

For several days before his death at their house in Thornton, Fife, the two women had left Liam, Rachel’s son, suffering from a fractured arm and broken leg.

Liam Fee

Liam was found dead at his home in Fife in March 2014

Rather than seek medical treatment, they gave him painkillers, even though they appreciated the severity of his injuries.

Analysis of their mobile phones revealed Google searches for: “Can you die from a broken hip?”

The pair, originally from Ryton in Newcastle, were also found guilty of ill-treating two other seven-year-old boys in their care, including the one they tried to implicate in Liam’s death.

They tied one of the boys inside a cage and bound the other to a chair in a locked room with caged rats and snakes, warning that their pet boa constrictor might eat him if he was bad.

Other abuse included forcing the boys to eat dog excrement and stand under cold showers for prolonged periods.

Detective Superintendent Gary Cunningham, of Police Scotland, told Hype Judge: “It has been horrific when you see the abuse that these boys have suffered, and the abuse and neglect that caused the death of Liam.

“It’s had a significant impact on everyone involved in the investigation and the community.”

Fife Council has announced it will review the efforts of child protection agencies who were alerted to Liam.

On separate occasions, a health visitor and nursery staff reported concerns about cuts and bruises that he had sustained.

The trial heard that a case worker had been assigned to monitor Liam’s family but when that individual fell ill, Liam’s case “fell off the radar”.

Douglas Dunlop, vice-chair of Fife’s Child Protection Committee, told Sky News: “Liam’s death is a tragic, deeply distressing event that has greatly impacted on everybody who was involved.

“It is important we learn from cases such as Liam and that is why we are undertaking a significant case review which will examine the full circumstances that led up to his death.”