A six-year-old girl schoolgirl who was raped and murdered was smothered to death, a jury has been told.

A 16-year old boy, who cannot be named for legal reasons, denies abducting Alesha MacPhail from the home her grandparents shared with her dad on the Isle of Bute, sexually assaulting and killing her and attempting to hide evidence.

Her body, which bore 117 separate injuries, was found in a wooded area on the island on 2 July last year.

Pathologist John Williams told a trial at the High Court in Glasgow he carried out a post-mortem examination of her body and the cause of death was “pressure to the neck and face.”

He said the injuries to Alesha’s neck and face were consistent with being gripped, and those to her nose and mouth were consistent with “smothering”.

He added it was possible her windpipe was pushed shut.

Williams also said Alesha had suffered “catastrophic” injuries to her genital area, more severe than he had ever seen before. He added it was unclear if the injuries had been caused by a body part or an object. 

The court was shown graphic pictures of the injuries, which judge Lord Matthews warned were “distressing”.

The pathologist said the soles of her feet were clean, consistent with her being picked up or otherwise taken to where she was found.

The court also heard from the 16-year-old accused’s mother, who said her son had been drinking with friends at home on July 2.

She said they argued about damage to furniture and then she thought he had gone to bed.

The following day she helped search for Alesha and later checked her CCTV system covering the front and back of her home, installed as a precaution when her mother, who suffered from dementia, had lived with her. She said she saw her son on the footage.

The court was shown footage in which she identified her son leaving the home at 1.54am on July 2, wearing all black, and returning at 3.35am no longer wearing his black top.

At 3.44am, a light is turned on in the bathroom and he is seen leaving a minute later wearing only shorts and carrying an item.

The mother said she told her son about the footage and asked him why he was out, to which he said: “I don’t know, I might have been looking for my phone.”

She asked him if he knew anything about the missing girl and he said “no”.

His mother later phoned police to “eliminate” her son from inquiries, saying: “Obviously I really didn’t think he had anything to do with it whatsoever.”

She said described her son as “clever at maths”, “well-liked” and said he had “lots of friends”.

The accused has lodged a special defence blaming Toni McLachlan – the girlfriend of Alesha’s father Robert MacPhail – for the killing.

During her evidence to the court on Wednesday she insisted she had had nothing to do with the girl’s death, telling jurors: “I loved her to pieces.”

The accused also denies attempting to defeat the ends of justice by disposing of clothing and a knife.

The trial continues.