A Sydney lawyer representing victims of sexual abuse in claims against the Maitland-Newcastle Catholic Diocese says out-of-court settlements made by the church could be in excess of $15 million.

The Australian newspaper reports that the diocese has settled cases with around 100 sexual abuse victims.

The Diocese will not confirm the reports and Bishop Bill Wright says it is not in anyone's best interest to make known the total number of settlements or the amount involved.

But solicitor John Ellis from Sydney firm David Beggs and Associates says he has acted on behalf of victims and believes the number could be higher.

"We've acted in probably about 60 claims or more against the Diocese over the last three years," he said.

"And we're aware that there's been other firms who have brought claims, we're also aware a number of claims have been brought directly to the Diocese without any solicitors involved.

"So I wouldn't be surprised if the number of claims that this Diocese has dealt with over recent years is well in excess of the number that's talked about."

Mr Ellis believes the number of sexual abuse claims made against the Maitland-Newcastle Catholic Diocese is far higher than any other Diocese in the country.

He says the diocese has a dark history.

"What has happened in that diocese over the period, and the claims that we've dealt with go over several decades, is just an extraordinary," he said.

"Concentration of claims over that period of time is quite in excess of anything we're aware of of any other diocese."

Mr Ellis supports calls for a Royal Commission into clergy sexual abuse.

He says an independent probe is long overdue.

"I really think that what people need to see is that there is transparency and openness and accountability about these issues," he said.

"And I think the situation with the church is that whatever it were to do internally and whatever information it were to make available voluntarily would always leave people with a doubt.

"It does need to be a Royal Commission."