It is known that St. Padre Pio withheld absolution.
‘One day Padre Pio didn’t give absolution to a penitent and he told him: “If you go to confess to another priest to have gain absolution you will go to hell together with him”. He meant that the sacrament of confession is profaned by people that don’t want to change their lives. They are guilty in front of God.’ Source: Padre Pio Webservices.
Below are discussions re priests withholding absolution:
“Third, the priest must grant absolution—and may in fact withhold it if he sees no contrition or intention to amend one’s life. For example, if someone confesses cohabitation before marriage without intending to change the situation, the priest certainly ought to withhold absolution. And so with any sin.” Source: Catholic Culture
“Looking at Canon Law:
Can. 980 If the confessor has no doubt about the disposition of the penitent, and the penitent seeks absolution, absolution is to be neither refused nor deferred.
The corollary, therefore, is that if there is doubt, absolution may be deferred or refused. Further, canon law reserves several excommunication offenses to the bishop or even Rome.
So yes, absolution can be withheld for cause.” Source: Catholic Answers Forum.
“Origen, Tertullian, and the followers of Novatian principles were unwilling to grant that the Church had a right to absolve from such sins as apostasy, murder, and adultery.
“In this matter, see Tertullian, “De Pudicitiâ”, which is simply a vehement protest against the action of the Pope, whom Tertullian accuses of presumption in daring to forgive sins, and especially the greater crimes of murder, idolatry, etc. Tertullian himself, before becoming a Montanist, asserts in the clearest terms that the power to forgive sins is in the Church.” Source: Catholic Encyclopedia
“In order that the minister of the Sacrament may know the dispositions of penitents with a view to granting or withholding absolution . . . ” Source: Apostolic Letter Misericordia Dei. Pope John Paul II.