A mother's failure to get help for her injured two-year-old does not make her a murderer, a court has heard.

Rachel Fee or Trelfa, 31, is accused along with her civil partner Nyomi Fee, 29, of a fatal assault on toddler Liam Fee, who died at a house in Fife on March 22, 2014.

The pair claim another boy, who cannot be identified, was responsible for his injuries.

Trelfa's lawyer told the trial at the High Court in Livingston on Thursday that she had "no motive" for attacking her son and was guilty only of the "unforgivable crime" of failing to seek medical aid for Liam for a suspected broken leg in the days before his death.

Brian McConnachie QC said: "By failing to get medical help, his mother Rachel Fee committed an unforgivable crime and in due course she will be rightly and justly punished for that.

"That does not make her a murderer. Tragedy is an overused word in this court but the death of Liam Fee is a real, genuine tragedy."

He told the jury: "Do not compound that tragedy by convicting Rachel Fee of the murder of her son when there's not a shred of evidence to support that contention.

"The Crown case is one of illusion, of smoke and mirrors."

Mr McConnachie also urged members of the jury not to let any emotional feeling sway their judgement, telling them: "This is as harrowing a case as any jury is likely to have to listen to."

He said video interview evidence given by two boys which was led by prosecutors was "contaminated" because of the way the interview process was carried out, and that there was no direct evidence that Trelfa ever assaulted Liam.

Both defence counsels say there is a case for Liam having been assaulted by another boy who they claimed had shown sexualised and violent behaviour towards the toddler in the past.

Mark Stewart QC, defending Fee, told jurors on Wednesday: "He (the boy) was the one, and only him, who was responsible for harming Liam that day."

Prosecutors say that while the case against the pair is circumstantial, there is "clear and compelling" evidence against the women, including that given by the two boys in video interviews.

Alex Prentice QC has asked the jury to find the pair guilty of what he described as "a course of violent and cruel treatment towards the children" and an escalation of violence towards Liam leading up to his death.

The women are accused of eight charges in total, including the ill treatment and neglect of the children, assault, and murder.

They are also accused of attempting to defeat the ends of justice by falsely incriminating another boy for Liam's death.

Lord Burns will continue directing the jury on Friday before releasing them to consider a verdict.

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