Tom O’Gorman, a religious writer and former journalist, was killed at his home in the Irish capital after reportedly getting into an argument over a chess move with his lodger, a 34-year-old from Palermo in Sicily, the Irish Independent reported.
O'Gorman, 39, is also reported to have had his lung removed during the horrific attack.
The Italian allegedly stabbed O’Gorman several times with a kitchen knife and beat him over the head with a dumbbell, the newspaper said.
He then calmly phoned the police to tell them what had happened, later telling officers that he had eaten the man’s heart.
A source, however, told the Irish Independent that O’Gorman’s heart was intact but “a lung was removed from the body and has not been located”.
When contacted by The Local, a police spokesman was unable to confirm details of the crime but said the Italian man was due to appear in court on Monday morning.
O'Gorman is understood to have been a former journalist with The Voice Today, a Roman Catholic newspaper, and a graduate of University College Dublin.
More recently, he was a researcher with the Iona Institute, a Dublin-based Catholic lobby group.