Experts now believe that the practice of burying butter in Irish boglands was linked to the burial of ritually-killed humans and other artifacts as part of a kingship and sovereignty ritual.
It had been believed that butter was buried in bogs to conserve it for future consumption but a review of the finds by experts has found that most were located on important land boundaries.
A re-examination of bog bodies has led to the conclusion that their execution may have been linked to the inauguration of a king as depicted on an Iron Age cauldron from the Gundestrup bog in Denmark.
This is believed to show the inauguration of a king in a ritual which closely corresponds to the Irish tradition.
According to the current edition of Archaeology Ireland, the bog burials involving human sacrifice in the early Iron Age can now be seen to be part of a wider practice of ritual deposition of bog butter, quernstones and a sickle from one site.
"These are reminders that a central function of the marriage of the king and the earth goddess was to ensure the fertility of the land and the wellbeing of the people who were dependent for survival on reliable yields of corn, milk and milk products," according to Eamon P Kelly keeper of antiquities at the National Museum of Ireland.
Mr Kelly was one of a team which reviewed the bog butter finds, most of which dated from the Iron Age through to medieval times.
Nine samples of Irish Iron Age bog butter were all found on or in close proximity to boundaries, five near barony boundaries and three near parish boundaries.
The report said the location of butter samples would seem to be linked to the wider practices of depositing an extensive range of weapons, personal ornaments, bridle bits, leading pieces, yokes, cauldrons and feasting vessels.
"It may be noted that one of the samples of bog butter was found in the same bog as an Irish Iron Age bog body, in the townland of Baronstown West, Co Kildare," said the report. It said a mapping project of bog butter finds is currently being undertaken by the National Museum.