Illinois' attorney general's office on Wednesday accused the Catholic Church of dramatically low-balling the scope of allegations of clergy sex abuse, saying her investigators found at least 500 additional accusations against priests and clergy - compared with the 185 cases the church has found credible.

Lisa Madigan's office acknowledged on Wednesday that a charge that has been found credible is not the same thing as a simple accusation. However, she alleged in a statement that a probe her office opened into the Church in August is finding Catholic leaders are failing to dig deep into the guilt of their clerics. The probe "has revealed that allegations frequently have not been adequately investigated by the dioceses or not investigated at all," the statement said.

Some state Catholic leaders, under siege during a year of global scandal over bishops' handling of abuse cases, pushed back. The crux of Ms Madigan's announcement was unfair and "false", said William Kunkel, counsel for the Chicago archdiocese.

"The idea that clergy sexual abuse of minors is more extensive than [we] reported is just false," he said. "We don't see lawyers, doctors, schools publishing lists like this," he said of allegations not found to be reasonably credible. "It's not fair to put out a list of people accused, any more than it would be fair to put out a list of accused reporters."

Ms Madigan's office is one of more than a dozen to open state investigations this year into Catholic handling of abuses cases. But Wednesday, some experts said, seemed to up the ante because it pushed on a controversial topic that has angered Catholics from left to right - whether the Church, under fire since the early 2000s, is really coming clean with its lists. Scandals at the top of the church in 2018 have resulted in a slew of dioceses and religious orders releasing their lists of credibly-accused priests.

The problem: There is no standard within the Catholic Church for what constitutes "credible" accusations, and many Catholics and members of the public are sceptical church leaders are coming forward to civil authorities and the public with everything they have.

Ms Madigan, said long-time survivor advocate Terry McKiernan, is trying to force the church to produce lists that are more transparent and meaningful. Even in recent weeks, Mr McKiernan said Wednesday, some lists around the country are being shown to not have included names they should have.

"There's a big debate about what 'credible' means, but these lists are clearly incomplete in a number of ways. Or at least there is lag before names are added," he said. "Let's face it, an allegation is an allegation, and very few are unsubstantiated if the diocese does the work to look into it."

Dioceses are dragging their feet on substantiating allegations "because they don't want to acknowledge the crisis they're in," Mr McKiernan said.

Ms Madigan's announcement comes as the Catholic Church is being forced in a way it never has to address the crisis, in particular the lack of accountability that exists for the bishops who manage the Catholic Church. The US bishops have an unprecedented retreat planned for the first week of January, and Pope Francis has convened a first-of-its-kind meeting in February. The primary issue, which has come to the fore in a year with one bishop after another losing his position, is how to bring more transparency and accountability to church leaders.

Earlier on Wednesday, the Vatican announced that a Los Angeles bishop was being removed after a review of a child sex abuse charge from the 1990s.

Pope Francis visits Ireland – in pictures Show all 55 1 /55 Pope Francis visits Ireland – in pictures Pope Francis visits Ireland – in pictures Pope Francis celebrates the Holy Mass at the Phoenix Park, in Dublin AP Pope Francis visits Ireland – in pictures Pope Francis arrives at Phoenix Park for a Papal Mass of the World Meeting of Families in Dublin EPA Pope Francis visits Ireland – in pictures A vigil takes place at the site of the mass grave which contained the remains of 796 named babies from the Bon Secours Mother and Baby home in Tuam. The vigil coincides with the Phoenix park mass which is taking place in Dublin held by Pope Francis. Excavations at the site in 2017 revealed underground structures which held babies bodies with ages ranging from 35 weeks to three years old with most of the dead buried in the 1950s when the facility was run by the Bon Secours Sisters, a Catholic religious order of nuns who received unmarried pregnant women to give birth Getty Pope Francis visits Ireland – in pictures An aerial view of the crowd at Phoenix Park Getty Images Pope Francis visits Ireland – in pictures Children queue for communion during Pope Francis' closing Mass PA Pope Francis visits Ireland – in pictures The Stand4Truth rally gathers outside a former Magdalene laundry in Dublin as part of the demonstrations against clerical sex abuse PA Pope Francis visits Ireland – in pictures Pope Francis leads the Holy Mass at Phoenix Park AFP/Getty Pope Francis visits Ireland – in pictures Pope Francis arrives to celebrate the Holy Mass at the Phoenix Park AP Pope Francis visits Ireland – in pictures The names of the victims are read out as a vigil takes place at the site of the mass grave which contained the remains of 796 named babies from the Bon Secours Mother and Baby home Getty Images Pope Francis visits Ireland – in pictures Pope Francis leads the Holy Mass at Phoenix Park AFP/Getty Pope Francis visits Ireland – in pictures A member of the clergy carries a bowl of incense PA Pope Francis visits Ireland – in pictures Pope Francis celebrates the Holy Mass at the Phoenix Park, in Dublin, Ireland, Sunday, Aug. 26, 2018. Pope Francis is on the second of his two-day visit to Ireland. (AP Photo/Matt Dunham) Matt Dunham AP Pope Francis visits Ireland – in pictures A vigil takes place at the site of the mass grave which contained the remains of 796 named babies Getty Images Pope Francis visits Ireland – in pictures Members of the public pray as they watch Pope Francis deliver a Papal Mass of the World Meeting of Families at Phoenix Park EPA Pope Francis visits Ireland – in pictures Pope Francis attends the closing Mass at the World Meeting of Families at Phoenix Park in Dublin PA Pope Francis visits Ireland – in pictures Pope Francis passes by a banner of a protester as he leaves St Mary's Pro-Cathedral AP Pope Francis visits Ireland – in pictures Pope Francis speaks during his visit to the Capuchin Day Centre for Homeless in Dublin AP Pope Francis visits Ireland – in pictures Pope Francis waves to the waiting crowds on Christchurch PA Pope Francis visits Ireland – in pictures Pope Francis waves to the waiting crowds on College Green PA Pope Francis visits Ireland – in pictures Members of the public wave at Pope Francis as he travels through the city Getty Images Pope Francis visits Ireland – in pictures Pope Francis laughs as he leaves St Mary's Pro Cathedral during his visit to Dublin Reuters Pope Francis visits Ireland – in pictures Two boys wave flags after climbing a post as they wait for Pope Francis Getty Pope Francis visits Ireland – in pictures Pairs of baby shoes are hung from black ribbons on Gardiner Street in Dublin in memory of the children who died at the Bon Secours Mother and Baby Home in Tuam, Co Galway PA Pope Francis visits Ireland – in pictures Crowds on O'Connell Street PA Pope Francis visits Ireland – in pictures DUBLIN, IRELAND - AUGUST 25: (NO SALES) In this handout image provided by Maxwell Photography for 2018 WMOF2018, Pope Francis and Taoiseach Leo Varadkar greet a child at Dublin Castle on August 25, 2018 in Dublin, Ireland. Pope Francis is the 266th Catholic Pope and current sovereign of the Vatican. His visit, the first by a Pope since John Paul II's in 1979, is expected to attract hundreds of thousands of Catholics to a series of events in Dublin and Knock. During his visit he will have private meetings with victims of sexual abuse by Catholic clergy. 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REUTERS/Clodagh Kilcoyne CLODAGH KILCOYNE Reuters Pope Francis visits Ireland – in pictures Taoiseach Leo Varadkar delivers a speech watched by Pope Francis in St. Patrick's Hall at Dublin Castle WMOF2018/Maxwell Photography/Getty Pope Francis visits Ireland – in pictures Protesters hold banners during a demonstration against clerical sex abuse, in Dublin Reuters Pope Francis visits Ireland – in pictures Pope Francis plants a tree during a meeting with Irish President Michael D Higgins, at Aras an Uachtarain PA Pope Francis visits Ireland – in pictures Pope Francis walks with the President of Ireland Michael Higgins at Aras an Uachtarain WMOF2018/Maxwell Photography/Getty Pope Francis visits Ireland – in pictures Pope Francis arrives at Dublin International Airport, at the start of his two-day visit to Ireland, August 25, 2018. 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Since Ms Madigan's probe began in August, her spokesperson said, the six Illinois dioceses have had to add 45 new names to their various lists of credibly accused priests. This reflects a lack of candour, said the office's communications director, Maura Possley, and it is why Ms Madigan publicised the number of accusations.

Asked if it was fair to compare these two separate buckets of cases - the church's list of priests it deemed credibly accused and the AG's additional list of accused priests – Ms Possley said it was.

Ms Madigan "felt it was important for transparency purposes and for survivors to know she's taking this seriously," Ms Possley said. "She has said from the get-go, she thinks they have a moral obligation to provide a full and accurate accounting of child sexual abuse."

James Towey, president of Ave Maria University, said Ms Madigan's report - and those of other state attorneys general - should be clearer as to which allegations are old and which are new. That said, Mr Towey called Ms Madigan's preliminary report "further evidence that the scale of the scandal is scandalous. I think the number are shocking."

Cardinals, bishops and other top clergy say they want to make amends and help victims heal, but the church's glacial pace of revealing allegations runs counter to that stated goal, said Mr Towey, who was a lawyer and a Bush administration official before taking the helm at Ave Maria University, one of the nation's most prominent conservative Catholic colleges.

"It won't start until all the names are out there. The church has to clean up its act," Mr Towey said. "The fact is - this is a mess of the Church's creation and all of us, laity and ordained, have to come together and fix it."