Lord Advocate Colin Boyd has asked one of his predecessors to clarify an apparent attack he made on a key witness in the Lockerbie trial.
A Sunday newspaper reported remarks by Lord Fraser
Remarks by Lord Fraser of Carmyllie, who issued the indictment against two Libyans charged with the 1988 bombing, were reported in a Sunday newspaper.
Lord Fraser said he had attempted to correct the "erroneous interpretation" of his views on Tony Gauci's evidence.
He said he had written to Mr Boyd expressing his dismay over it.
The bombing of Pan-Am flight 103 above Lockerbie caused the deaths of 270 people.
Abdelbaset Ali Mohmed al-Megrahi was convicted of smuggling a bomb aboard the New York-bound flight on 21 December, 1988.
The former Libyan intelligence officer was found guilty after a trial by a specially convened Scottish court at Camp Zeist in the Netherlands.
His co-accused, Al Amin Khalifa Fhimah, was acquitted.
On Friday, Mr Boyd said that remarks attributed to Lord Fraser expressed doubts about Mr Gauci, the Maltese shopkeeper who sold the clothing to Megrahi which was used to pack the bomb suitcase.
Mr Boyd said: "It was Lord Fraser who, as Lord Advocate, initiated the Lockerbie prosecution.
"At no stage, then or since, has he conveyed any reservation about any aspect of the prosecution to those who worked on the case, or to anyone in the prosecution service."
The lord advocate said that the position of the Crown both before and after Lord Fraser left office in 1992 had always been that Tony Gauci was a reliable and credible witness.
He said that the three High Court judges who saw Mr Gauci giving evidence said that they found him entirely credible.
Lord Fraser said: "I have already told the Crown Agent in two telephone calls that I have no aspersions to cast on Tony Gauci's evidence."
"Indeed such was the thoroughness of the investigation and the way in which it developed that I probably would place greater emphasis and credibility on Mr Gauci's evidence than any of my successors as lord advocate."
He added: "As the present lord advocate wholly correctly asserts, however, any view of mine is essentially irrelevant. What matters is the judgment of the court.
"Three of Scotland's High Court judges heard him give evidence properly subject to cross-examination and they were specific in their conclusion that he was entirely credible."