The family of Amanda Duffy have condemned the Crown Office and procurator fiscal, saying they mishandled a petition for a retrial of Francis Auld.

Auld was accused of murdering Ms Duffy in 1992. But due to a lack of evidence, a not proven verdict was reached.

But after Auld died of cancer last month, the family hit out at how the case was handled.

In a letter to Lord Advocate James Wolfe QC, the family accused the courts of several failures before a double jeopardy case:

- Not checking that they were prepared before announcing they were going to try again.

- Checking they had carried out proper due diligence they would have found they had lost most of the original evidence which had a major bearing on what they had at their disposal.

- Having no transcript - this had to be supplied by the Duffy Family.

- Making false promises they could not substantiate time and again.

- Staffing inconsistencies after the senior police officer retired during the case.

- The Advocate Depute to present the application was changed at almost the last minute.

The family claim the Crown failed to use "new DNA evidence" as part of their application, stating: "What is abundantly clear is that the individual or individuals that made the decision not to include the DNA did not have either the courage of their convictions or faith in the Judges' interpretation of the Act."

Ms Duffy was murdered in May 1992. Her body was discovered naked in a car park in Hamilton, having being beaten and strangled to death.

Auld admitted to being with Ms Duffy the night of her murder, but always denied being involved.

The Duffy family are calling for an overhaul of the Double Jeopardy Act and plan to continue their fight to have the not proven verdict banned.