David Black's son Kyle paid tribute to his father, calling him, "the wee man with the big smile," at his funeral service in Cookstown, county Tyrone.
His daughter Kyra told mourners that she is very proud of her special hero and said that her love for him will be everlasting.
The family Minister told the congregation that David Black's killers were, "murderous thugs and bloodthirsty criminals."
Three men, aged 31, 29 and 44, have been arrested following the killing of prison officer David Black in Northern Ireland.
Leaders in Northern Ireland have condemned the "horrific" motorway murder of a veteran prison officer by suspected dissident republicans.