A former top Vatican official has accused Pope Francis of having known of allegations of sex abuse by a prominent US cardinal for five years before accepting his resignation last month, and has called on the pontiff to resign.

In an 11-page letter given to conservative Roman Catholic media outlets during the Pope’s visit to Ireland, Archbishop Carlo Maria Vigano said he had told Pope Francis in 2013 Cardinal Theodore McCarrick had faced extensive accusations of sexually abusing lower ranking seminarians and priests.

Vatican officials declined to make an immediate comment on the letter on Sunday.

McCarrick became the first cardinal in living memory to resign his position in the church leadership, after a review concluded claims he had sexually abused a 16-year-old boy were credible.

He was one of the highest ranking church officials accused of sex abuse in a scandal that has rocked the 1.2 billion member faith since reports of priests abusing children – and bishops covering up for them – were first published by The Boston Globe in 2002.

Since then, patterns of widespread abuse of children have been reported across the United States and Europe, in Chile and Australia, undercutting the church’s moral authority and taking a toll on its membership and finances.

Mr Vigano said, in the letter reported by the conservative US National Catholic Register, he had told Pope Francis of allegations against McCarrick in June 2013, shortly after the new pontiff’s election as pope by his fellow cardinals.

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. (Photo by WMOF2018/Maxwell Photography via Getty Images) Handout WMOF2018/Maxwell Photography/Getty Pope Francis visits Ireland – in pictures Pope Francis memorabilia on sale on O'Connell Street PA Pope Francis visits Ireland – in pictures Pope Francis arrives at St Mary's Pro-Cathedral during his visit to Ireland to attend the 2018 World Meeting of Families AFP/Getty Pope Francis visits Ireland – in pictures Pope Francis waves to the waiting crowds on O'Connell Street PA Pope Francis visits Ireland – in pictures Pope Francis addresses the congragation at St Mary's Pro-Cathedral AFP/Getty Pope Francis visits Ireland – in pictures Stephen O'Brien selling bottles of holy water from the St Mary's Pro Cathedral PA Pope Francis visits Ireland – in pictures Pope Francis prays inside St Mary's Pro Cathedral Reuters Pope Francis visits Ireland – in pictures A man waves a rainbow flag behind a model of a pope which stands in the window above a bar Getty Pope Francis visits Ireland – in pictures People hold a banner against Pope Francis on the way to St Mary's Pro-Cathedral AP Pope Francis visits Ireland – in pictures Nuns wait by the side of the road for Pope Francis Reuters Pope Francis visits Ireland – in pictures A model of a pope is placed in the window above a bar as crowds wait for Pope Francis to travel through the city Getty Pope Francis visits Ireland – in pictures Crowds on O'Connell Street, Dublin waiting to see Pope Francis as he travels in the Popemobile PA Pope Francis visits Ireland – in pictures Pope Francis waves to wellwishers as he arrives at Dublin Airport Getty Pope Francis visits Ireland – in pictures 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 PA Pope Francis visits Ireland – in pictures Pope Francis talks to journalists aboard a plane flying from Fiumicino aiport to Dublin AFP/Getty Pope Francis visits Ireland – in pictures LGBT protestors from Dublin Pride and We Are Church with flags and umbrellas on Ha'Penny Bridge, Dublin to remember the victims of clerical sex abuse ahead of the start of the visit to Ireland by Pope Francis PA Pope Francis visits Ireland – in pictures Pope Francis disembarks from the aircraft as he arrives at Dublin Airport Getty Pope Francis visits Ireland – in pictures Woman wait for Pope Francis to drive past, in Dublin Reuters 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. 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. REUTERS/Clodagh Kilcoyne CLODAGH KILCOYNE Reuters Pope Francis visits Ireland – in pictures Pope Francis, center, is flanked by Irish Prime Minister Leo Varadkar, right, as they arrive to meet authorities, in Dublin AP Pope Francis visits Ireland – in pictures Protestors wearing baby shoes, to signify the children who died in mother and baby homes in Ireland, protest in Dublin ahead of the start of the visit to Ireland by Pope Franci PA Pope Francis visits Ireland – in pictures Pope Francis exchanges gifts with Irish Prime Minister Leo Varadkar AFP/Getty Pope Francis visits Ireland – in pictures Pope Francis speaks with President Michael D Higgins in his study during a visit to Aras an Uachtarain in Phoenix Park, Dublin PA Pope Francis visits Ireland – in pictures Navy band march prior to the arrival of Pope Francis at the Presidential residence in Dublin AP Pope Francis visits Ireland – in pictures Eddie McGuinness from Dublin LGBTQ Pride carries a rainbow flag across Ha'Penny Bridge, Dublin ahead of the start of the visit to Ireland by Pope Francis PA Pope Francis visits Ireland – in pictures A message left by Pope Francis in the visitors book at Aras an Uachtarain in Phoenix Park PA

“He knew from at least 23 June, 2013, that McCarrick was a serial predator,” said Mr Vigano, who served as the Vatican’s ambassador to the United States at the time.

“Pope Francis must be the first to set a good example for cardinals and bishops who covered up McCarrick’s abuses, and resign along with all of them.”

Mr Vigano’s letter railed against “homosexual networks present in the church” – the word “homosexual” appears 18 times, while the word “child” appears only twice, in both cases in the titles of church documents Mr Vigano sites.

Pope Francis vowed, on Saturday, to end the sexual exploitation of children by clergy during a highly charged visit to Ireland and, according to victims, said the corruption and cover up of abuse amounted to human excrement.