THE government was baffled over a major hunt by gardai and the National Museum in the Dublin Mountains for the Irish crown jewels, which had vanished over 70 years previously.
The gems were stolen from a safe in Dublin Castle on July 6, 1907, in arguably Ireland's most famous robbery.
The Department of An Taoiseach was briefed on new information which came to light in September 1983 about a possible hiding place for the gems.
Five major searches of an area in the mountains were conducted over August and September by gardai and National Museum officials, assisted by a metal detector. Nothing was found.
Documents in the state archives reveal that successive governments had closely followed all rumours about the gems over the decades.
The gems, valued in 1983 at over IR£2m, have a current value of around €14m.
They were donated to Ireland by King William IV in 1830 to be used on ceremonial occasions by the Order of St Patrick.
They were stored in a special safe in the library of the Office of Arms in the Bedford Tower of Dublin Castle. However, the safe was not installed in a special strong room because the room was accidentally constructed with too narrow an entrance to allow it to be fitted.
The gems were dramatically stolen in 1907 just days before King Edward VII was due to begin a state visit to Dublin.
The theft was hugely embarrassing, both for the Royal Irish Constabulary and the Dublin Castle authorities, because King Edward was due to invest Lord Castletown as a knight in the Order of St Patrick.
Even more embarrassing was the fact that the Dublin detective headquarters was located barely 100 yards away.
Despite police having a number of suspects, no one was ever charged. Those questioned included the Chief Herald, Arthur Vicars; his assistant, Pierce O'Mahony, a son of 'The O'Mahony'; and Francis Shackleton, the brother of the Irish Antarctic explorer Ernest.
Both O'Mahony and Vicars were subsequently shot dead, one in 1914 and the other in 1920. Shackleton was later jailed in the UK for fraud and, on his release, vanished.
The theft of the gems has since settled firmly into Irish legend. In 1927, it was rumoured Taoiseach William Cosgrave was in negotiations to buy back the gems from a Paris jeweller for IR£3,000.