Documents relating to the school massacre, released after a 100-year secrecy rule was lifted, show how police investigated claims of a Masonic conspiracy.
But they appear to give little support to lingering suspicions of a cover-up involving police, politicians and other senior public figures.
Among the 3,000 letters and reports uncovered is correspondence between a member of public and Lord Cullen's office regarding suggestions that the gunman, Thomas Hamilton, and senior police, who were aware of concerns over summer camps and clubs he ran, were Masons.
In one letter, the member of public, whose name has been concealed, wrote to Lord Cullen's office after a date for a preliminary inquiry hearing was set.
The letter, dated 11 April 1996 - less than a month after Hamilton killed 16 pupils and a teacher at Dunblane Primary School - said: "It is in the public interest that Lord Cullen be asked if he is a Freemason, given the widely held view by the public that Thomas Hamilton's Masonic affiliation was probably the reason that the Ombudsman overturned an earlier decision by Central Regional Council in 1983 to prevent Hamilton from running youth clubs, and that his Masonic affiliation probably facilitated his application for a gun licence."
The letter-writer said anyone involved in the inquiry who turned out to be a Freemason should be forced to resign - and that included Lord Cullen.
The letter went on: "It is far too important to allow the Masonic implication to be whitewashed by furtive operations in the Freemasons, intent only in 'diverting a discourse' - a Masonic ruse - from the involvement of Freemasons and Freemasonry."
A handwritten note, apparently written by court staff after consulting with Lord Cullen, is marked "verbal response" and dated 18 April. It says "taken aback by the letter" and "not a Freemason, never has been".
Hamilton wrote scores of letters to police, council officials, MPs and even the Queen, claiming he had been the victim of a grand conspiracy to prevent him running boys' clubs.
In a statement given to Central Scotland Police in June 1996, an unnamed Grand Lodge of Scotland leader said he was aware of press speculation that Hamilton was a Mason, but said he did not think this was true as it "would have come to light immediately after the Dunblane incident".