There are two questions weighing heavily on abuse survivor Peter Gogarty's mind — how people who claim to believe in and preach the Gospel could prey on and sexually abuse children, and how those who concealed the abhorrent crimes have never be held to account.

Key points: Peter Gogarty has asked the International Criminal Court to investigate senior Church officials

Peter Gogarty has asked the International Criminal Court to investigate senior Church officials His submission alleges the Church's hierarchy "acted with impunity in every national jurisdiction in the world"

His submission alleges the Church's hierarchy "acted with impunity in every national jurisdiction in the world" The case is complex and must pass several hurdles being considered by the prosecutor

The questions have consumed him and he is now taking the issue to the International Criminal Court (ICC), asking its prosecutor to investigate senior Catholic Church officials for what he calls crimes against humanity.

"This is about the cover-up of abuse," Mr Gogarty said.

"Specifically, this is about the fact that people in very senior roles in the Catholic Church knew what was going on with the child sexual abuse scandal and instead of protecting children in their care, they protected paedophile priests and brothers and other lay people.

"And really, the whole point of that was to protect their reputation and their assets."

For the last two years he has pored over endless legal texts and documents, has learnt the individual provisions of the International Criminal Court and reviewed countless records from the Vatican and Catholic Church.

At times, he said, going over other people's misery had forced him to deal with the re-awakening of his own trauma.

"Sometimes it's gotten me down a little bit. But not enough that it's put me off persevering with this," he said.

His submission, which lists more than 200 senior members of the church, alleges the organisation's hierarchy "acted with impunity in every national jurisdiction in the world".

"In every country where this abuse has been studied, the pattern of cover-up, protection of the church and disregard for children has been identified," the submission reads.

The document alleges that "successive popes have given exclusive management of the child sexual abuse issue within its ranks to the Congregation of the Doctrine of the Faith (CDF) … which has issued clear and unambiguous directives to all bishops and heads of Catholic religious congregations world-wide regarding the process for dealing with allegations of child sexual abuse".

Peter Gogarty says the work has reawakened his own trauma. ( ABC News: Nancy Notzon )

The Catholic Church was a focal point of the Royal Commission into Institutional Responses to Child Sexual Abuse.

The inquiry found "catastrophic failures of leadership of Catholic Church authorities over many decades" with allegations of child sexual abuse going unreported to police or other civil authorities and perpetrators allowed to stay in the ministry, either in the same location or moved without the knowledge of parishioners.

But since the royal commission, no individual has been held accountable for concealing abuse.

"After all of the findings of the royal commission, we still have the Catholic Church investigating its own behaviour and effectively telling us we learnt our own lesson, it'll all be OK from now on," Mr Gogarty said.

"Well I'm not satisfied with that. What I want is for the Catholic Church, as an organisation, to be held accountable for what it deliberately did to children — and all this from an organisation that claims to represent Jesus on Earth."

Does the submission have a chance?

Mr Gogarty is optimistic the case will fall within the ICC's statute and the prosecutor will choose to pursue the matter further.

But the case is extremely complex, and he acknowledges there are several hurdles for it to pass before it is even potentially considered by the prosecutor.

That is echoed by international criminal law expert Professor Andrew Byrnes from the University of New South Wales.

He believes the systemic concealment of child abuse does constitute an abuse of human rights, which could possibly fall within the jurisdiction of the court, but it would have to be shown that there was a state or organisational policy involved.

Peter Gogarty, pictured speaking outside court after Archbishop Philip Wilson's sentencing, admits his case faces many hurdles. ( ABC News: Nancy Notzon )

"The classic case that comes before the ICC arises out of a situation which has taken place within the borders of one country, possibly spilling over into the territory of another country," he said.

"This case on the other hand … is talking about a situation which goes across potentially dozens of countries and I think that raises a whole series of legal issues."

Professor Byrnes said the ICC was set up as a last resort to deal with very serious crimes where national justice systems have not adequately dealt with them. The court makes that assessment on a case-by-case basis.

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" … And the standard that's applied is that the court has to be satisfied that the state is unwilling or unable to genuinely take on a proper criminal investigation of the case," he said.

"I think it [Mr Gogarty's submission] has a chance and the prosecutor has taken on some complex cases.

"I think the real challenge is that because it is so complex and there are timing issues and other issues about liability."

That issue of time means the ICC cannot investigate any crime alleged to have happened before the court came into existence in 2002, nor can it investigate something alleged to have happened in a country before it became a signatory to the ICC's Rome Statute.

In 2011, another case looking at the concealment of abuse within the church was taken to the ICC, but it was declined by the prosecutor in 2013. It is understood the office could reconsider that decision upon submission of new evidence.

What do those watching the Vatican think?

Rome-based Robert Mickens, editor of La Croix International, a prominent Catholic online publication, said while the abuse of children and its concealment had been abhorrent, the church would likely have some confidence the submission would not proceed far.

"This kind of course of action of going to the ICC has been tried before and it's been unsuccessful, in the sense that the Holy See has never been convicted on these charges," he said.

Sorry, this video has expired Scott Morrison reads formal apology to survivors of child sexual abuse. (Photo: ABC News/Matt Roberts)

But Catholics themselves, Mr Mickens said, were likely to be divided on the issue, with some wanting to see more accountability.

"I suspect there's not going to be a lot of backlash to something like this, but probably some scepticism about whether or not this is going to go forward," he said.

"I think many Catholics will think good luck, but it probably won't get anywhere."

A case of this complexity could take years to take even the most basic steps within the ICC.

But Mr Gogarty believes whatever does happen in the future, survivors and their families deserve more than just words.

"We committed billions of dollars to our royal commission, we had a national apology from the Prime Minister and Opposition Leader. They were wonderful words, but if they're only words and there's no action to follow up on that then they will ring very hollow and child abuse survivors will feel as though they've been used all over again.

"We can't just say sorry, we know this happened to you, but no we're going to wait for all you people to disappear and hope that this doesn't happen again."

The Catholic Church in Australia and the Vatican have been contacted for comment.