The jury in the trial of two women accused of murdering toddler Liam Fee has been urged to find them guilty of "unyielding, heartless cruelty".

In his closing speech to jurors, advocate depute Alex Prentice QC urged them to find that Rachel Trelfa and her civil partner Nyomi Fee had carried out a course of "violent and cruel" treatment towards three children.

He said the evidence pointed to them showing "callous indifference" to the suffering of Trelfa's two-year old son Liam Fee and that they had "covered up" his injuries.

They deny murdering two-year-old Liam at a house near Glenrothes in Fife by repeatedly inflicting "blunt force trauma" to his head and body, as well as ill-treating two other young boys in their care, one of whom they blame for the toddler's death on March 22, 2014.

Mr Prentice said there had been an "escalation of violence" towards Liam leading up to his death.

He said the couple's failure to get help for the toddler when they knew he had serious injuries, including a broken leg and fractured arm, in the days leading up to his death was evidence of "art and part guilt" or a "common criminal purpose".

Mr Prentice told the jury the case had been "harrowing", adding: "You would really have to be made of granite not to have been moved by some of what you have heard."

He urged them to put aside any feelings of sympathy and judge the two women based on the evidence led over more than six weeks at the High Court in Livingston.

Mr Prentice said: "What I ask you to do is to find both the accused guilty of everything that is on this indictment. That's my invitation to you.

"You are entitled to do that. There is sufficient evidence led in this case which justifies the charges as they are."

Mr Prentice said while the case was circumstantial, there was "clear and compelling" evidence against the two women, including that given by the two other young boys in a series of video interviews shown to the jury.

He said: "If you stand back and look at all that it would entitle you to then consider that there has been an overall course of criminal conduct and it is that the accused together embarked upon a course of violent and cruel treatment towards the children."

Mr Prentice added: "There's a clear and compelling picture that emerges of the boys being ill-treated in a way that is completely unacceptable."

In his speech, Mr Prentice addressed the couple's claim one of the other young boys was responsible for Liam's death, noting the youngster in question had initially confessed he had "strangled" the toddler.

The jury have heard evidence Liam suffered a ruptured heart as a result of severe blunt force trauma.

Mr Prentice said: "Hand to the face or hand to the throat was not how Liam died. That is not the cause of death."

The advocate depute said the crime was murder because the two women had shown a "wicked indifference" to whether or not the "vulnerable and defenceless" Liam had lived or died.

He said: "As far as the crime is concerned there is simply no room for this being culpable homicide.

"To attack a defenceless young boy in that way with those consequences is murder."

Mr Prentice added: "They hid his injuries, they hid his pain and suffering and put their own interest first.

"They decided they would not get help for Liam despite what must have been an awful experience for him to put their own interest first."

He said if the jury was convinced both women had participated in a course of criminal conduct "it doesn't matter whether it's established who actually inflicted the fatal blow on March 22 because you are entitled to convict both of them".

Mr Prentice added: "The crime I say is one of murder and I ask you to convict both accused of the murder of Liam Fee."