APPEAL judges have cleared a mum of murdering her toddler son – but without saying why.

The mummified body of Paisley youngster Declan Hainey – who should have been celebrating his fifth birthday today – was found in a squalid flat in Bruce Road in March 2010.

By the time doctors were able to examine the body, it was impossible to tell how he had died.

Kimberley Hainey, 38, was found guilty of murdering her son and jailed for life.

Hainey went to the Court of Criminal Appeal in Edinburgh in January seeking to overturn the conviction which earned her a minimum 15-year sentence.

Edward Targowski, defending, argued that crucial evidence heard by the jury was flawed.

The lawyer questioned the claims of expert witnesses called by the Crown who said that tell-tale marks on his bones were signs of malnutrition.

The murder charge alleged that heroin addict Hainey had abandoned her son for long periods without food or drink while she partied, drank and took drugs.

At a hearing today, judge Lord Clarke said: "The court has come to the conclusion that the conviction of the Appellant of the murder of her baby son, Declan, must be quashed."

Lord Clarke said that during the appeal judges' consideration, issues had arisen which had not been discussed during the hearing in January. Because of that, the appeal court will hear from lawyers tomorrow before the judges reveal why they have overturned the conviction.

Hainey was also convicted of attempting to pervert the course of justice by keeping little Declan's body hidden. No grounds of appeal have been put forward on that charge.

The jury at her trial at the High Court in Glasgow in 2011 rejected Hainey's claim that she had woken one morning to find Declan dead in his cot and had not reported the tragedy because, as Mr Targowski explained: "She simply went into a downward spiral."

By the time Declan's body was found, he had not been seen alive for eight months.

A six-week trial heard how Hainey had kept family, neighbours and social services at arm's length, not allowing them to get close to the little boy.

After Declan's death, Hainey sold his clothes and toys to buy heroin.