Criminal prosecutors should be legally bound to provide full information to defence lawyers in advance of a trial, the Scottish Government was told yesterday.

The call came from a retired judge who said the information should include material favourable to the accused, even if it weakens the Crown case.

The call came from Lord Coulsfield in a report commissioned from him last year by the previous administration.

Lord Coulsfield, who retired in 2002, was one of three judges who presided at the Lockerbie trial in the Netherlands. He was asked by the previous administration to review the law in the light of a 2005 ruling by the Privy Council which overturned the convictions of two men, James Holland and Alvin Sinclair, on the grounds of "non-disclosure".

His findings include a recommendation for legislation requiring the prosecution to have regard to "the over-riding requirement of a fair trial".

The legislation should provide a definition of a duty of disclosure, and require prosecutors to disclose to the defence "all material evidence or information which would tend to exculpate the accused whether by weakening the Crown case or providing a defence to it," said the judge.

This already happens in England and Wales and Lord Coulsfield said: "I do not see that there is any practicable alternative in the short or medium term."

Non-disclosure by the Crown is a major issue in some of the most high-profile cases in Scotland, such as that of the Lockerbie bomber Abdelbaset Ali Mohmed al Megrahi who earlier this year was granted leave to launch a second appeal against his conviction.

Kenny MacAskill, the Justice Secretary, said: "The government welcomes this positive and helpful report. Disclosure is vital because it is essential that the defence have all the necessary information available to ensure a fair trial.

"Effective disclosure also contributes to a more effective criminal justice system and to earlier resolution of cases. I am indebted to Lord Coulsfield for his careful analysis. We will shortly publish a consultation paper to invite further views."

Elish Angiolini, Lord Advocate, said: "The report marks a significant step towards achievement of the required degree of clarity in this complex area of law and practice."