The purported head of St Vitalis of Assisi - the patron saint of genital disease - is to be auctioned in Co Meath this weekend.
The decapitated head, housed in a 17th century Queen Anne case, is being sold by an Anglo-Irish family from Co Louth and is valued at between €800 and €1,200.
There has been no official verification of the claim that it is the head of Vitalis, who was born in Umbria, Italy in 1295.
Despite living an early life marked by immorality and corruption, he was beatified after his death in 1370.
In efforts to absolve himself of his licentious past, Vitalis went on various pilgrimages to sanctuaries throughout Europe during his later life. On his return he entered the Benedictine monastery in Subiaco.
After leaving the monastery, he reportedly lived the remainder of his day as a poverty stricken hermit in Santa Maria di Viole, near Assisi.
It is said Vitalis wore only rags and rejected all forms of material wealth, except for the basket he used to fetch water from a local stream.
After his death, word spread of his holy reputation and ability perform miracles on those with bladder and genital problems.
The circumstances surrounding the arrival of the severed head in Ireland are unclear.
Reports suggest it was brought to Ireland by an Anglo-Irish couple who acquired it on the grand tour of Europe – a ritual of ascendancy for wealthy Europeans – during the 19th century.
It sat on display for many years in a family hallway but was later banished to an old outhouse.
Auctioneer Damian Matthews, who will put the macabre item under the hammer on Sunday, said while he cannot be certain it is the head of a saint, "it's certainly ancient, and it's certainly the head of someone".
The auction takes place at Annesbrook House in Duleek.