A priest who worked at the Marist College in northern Tasmania in the 1960s has been sentenced to four years in prison after pleading guilty to historical sex crimes.

Key points: Thomas Fulcher pleaded guilty earlier this month to three counts of indecent assault

Thomas Fulcher pleaded guilty earlier this month to three counts of indecent assault His two victims reported the abuse during the Royal Commission into Institutional Responses to Child Sexual Abuse

His two victims reported the abuse during the Royal Commission into Institutional Responses to Child Sexual Abuse Fulcher has been sentenced to four years jail with a minimum non-parole period of two years

He will serve a minimum non-parole period of two years.

Thomas Fulcher pleaded guilty in the Burnie Supreme Court earlier this month to three counts of indecent assault.

The court heard there were two complainants, both students at the school during the time Fulcher was the Marist College priest between 1960 and 1967.

Fulcher's victims, now aged in their 60s, came forward and reported the abuse during the Royal Commission into Institutional Responses to Child Sexual Abuse.

Fulcher, now aged 84, admitted he had made one boy perform a sex act in front of him and had also touched him on the genitals.

The priest then put on his confessional robes and took the boy's confession about what had just happened.

Fulcher told the second boy to drop his pants so he could check that he was "normal", then performed a sex act on him.

The victim told police that at the time he was abused, he had been taught he could not refuse to do what a priest had told him to do.

One of Fulcher's victims contacted the Catholic Church in 2002 about the abuse and underwent mediation with the church.

Fulcher retired after that but continued to volunteer as Chaplain to the sick and homeless in New South Wales.

The court heard while Fulcher was only being charged and sentenced over three incidents, the abuse of one of his victims continued every four to six weeks over two years.

'Complete betrayal of trust'

Father Tom Fulcher at Marist College, Burnie, in 1966. ( ABC News )

In sentencing Justice Helen Wood said Fulcher's offending was a "breach of trust at a profound level".

"The abuse was a complete betrayal of the children's trust, the parents' trust and that of society," she said.

She said when Fulcher performed confession after an incident of abuse: "It exclusively attributed the so-called guilt of his own wrongdoing to an innocent victim."

"The sacrament cloaked his conduct in secrecy."

The court heard Fulcher was abused by a priest as a child and did not know why he was "so blind to the impact on his victims when he should have had an even greater awareness as a result of his own experience".

'A reminder of mislaid trust'

Fulcher was ordained as a Catholic priest in July 1959 and the Catholic Church still lists him as a practising priest.

In a statement, Adrian Drane — the current principal of Marist Regional College, which was formerly named Marist College — said the case was "a reminder of the mislaid trust placed in some individuals, and is a dark part of Marist Regional College's history".

"One can only imagine the hurt, betrayal and absolute devastation of the survivors of abuse and their families," he said.

The Marist Fathers, which owned and operated Marist College Burnie before 1974, issued a statement expressing "deep regret and sorrow to the victims involved and their families".

"We recognise that conduct of this type perpetrated by a person in a position of trust is by definition abhorrent, unacceptable, deeply damaging and can never be excused or tolerated."