Crucial evidence which helped convict an addict mum of murdering her toddler son was flawed, appeal judges have been told.

It was claimed that, by the time doctors were able to examine the mummified body of Declan Hainey, they could not determine a cause of death.

But a QC said that, at a later trial, expert witnesses called by the Crown said that tell-tale marks on his bones were signs of malnutrition.

In 2011 heroin addict Kimberley Hainey, 38, was found guilty of murder, abandoning her son for long periods without food or drink in a flat in Bruce Road, Paisley.

She was jailed for life with a minimum of 15 years.

At the Court of Criminal Appeal in Edinburgh, Lords Clarke, Mackay of Drumadoon and Drummond Young, are hearing Hainey's bid to overturn her convictions for the 2010 murder and for attempting to pervert the course of justice by keeping Declan's body hidden in their squalid flat.

The judges were told that lines on growing bones were not necessarily a symptom of stress, illness or malnutrition.

Professor Sue Black said this view was "unsound science."

QC Edward Targowski told the appeal court 'Harris lines' may be signs of growth spurts, adding "There may be an explanation for them which is not sinister".

The hearing continues.