THE new Libyan Government's pledge to release documents relating to the Lockerbie bombing is a welcome step towards shining new light on exactly what led to the death of 270 people on December 21, 1988.

Despite the declaration by the Libyan ambassador to the UK Mahmud Nacua that all files would be open and everyone would know what happened with that crime, it is not clear how much information pertaining to the Gaddafi regime remains. Mr Nacua said it would be at least a year before Libya would be in a position to release whatever information it holds. This is frustrating for all those affected, especially for the families of those who died. But having heard so much conflicting evidence and suggestions for so long, the priority must now be truth rather than speed.

Willie Rennie, the Liberal Democrat leader at Holyrood, believes the prospect of new material increases the need for a public inquiry. This newspaper, which has revealed many significant developments in the Lockerbie case over a number of years, has consistently called for a public inquiry.

However, the change of regime in Libya presents an opportunity for further investigation. The Lord Advocate Frank Mulholland, who has made contact with the new regime, is hopeful of being able to send Scottish police officials to Tripoli to gather evidence that would reopen the wider plot to bring down PanAm 103. In particular, the extradition to Libya of Abdullah al-Senussi, the infamous head of Gaddafi's intelligence service at the time of the Lockerbie bombing, offers the prospect of obtaining previously unknown information.

Abdelbaset Ali Mohmed al Megrahi remains the only person convicted of the atrocity. Twenty-four years after the bombing, there remain so many unanswered questions and so many doubts about his conviction that his death in May last year, after being released from jail in Scotland on compassionate grounds, cannot be the end of the matter.

Although his first appeal was unanimously rejected, the Scottish Criminal Cases Review Commission (SCCRC) subsequently found a number of grounds which justified the case being referred back to the Court of Criminal Appeal. However, in 2009 the appeal process was abandoned and Megrahi was released from prison due to a diagnosis of terminal cancer.

Dropping the appeal was not a requirement for compassionate release but details of the SCCRC report revealed by The Herald last year intensified suspicion that he may have been urged to do so. What is not in dispute is that he could not have acted entirely alone. A new criminal investigation, assuming the co-operation of the authorities in Tripoli, will be essential to discover whether the operation was wider than Libya.

Grave disquiet about the handling of the Megrahi case continues. The concerns that Britain's worst-ever terrorist atrocity may additionally have become Scotland's greatest ever miscarriage of justice are now so deep-seated that a full public inquiry is required to establish the truth and restore faith in the justice system.