The president of the US Conference of Catholic Bishops said Wednesday that sex abuse allegations against former Cardinal Theodore McCarrick dating back decades raise serious questions about how the claims could stay secret for so long as the retired archbishop from Washington DC rose in prestige and power.

Cardinal Daniel N DiNardo said the allegations against his former colleague reveal a “grievous moral failure” and urged anyone who has experienced sexual abuse at the hands of the church to come forward. DiNardo reminded bishops in the US to take those reports seriously and contact the police when required.

“Both the abuses themselves, and the fact that they have remained undisclosed for decades, have caused great harm to people’s lives and represent grave moral failures of judgment on the part of church leaders,” he said in a statement.

“One way or another, we are determined to find the truth in this matter,” said DiNardo, who is also the archbishop of Galveston-Houston, in Texas.

The statement comes as church officials deal with abuse issues anew, more than a decade after the biggest mass clergy abuse settlements in US history and the release of tens of thousands of documents that were long sealed in priest personnel files.

In an open letter Tuesday, a contributor to the conservative Catholic magazine First Things urged Catholics to withhold donations to the US church until an independent investigation determines which US bishops knew about McCarrick’s misdeeds – a “nuclear option” aimed at making church members’ sense of betrayal heard.

In Pennsylvania, a Roman Catholic diocese on Wednesday identified 71 priests and other members of the church who had been accused of child sex abuse and said it was holding accountable the bishops who led the church for the past 70 years, announcing that their names will be stripped from all church properties.

McCarrick, the Washington archbishop from 2000 to 2006, was previously one of the highest, most visible Catholic church officials in the US and was heavily involved in the church’s yearslong response to allegations of priest abuse.

Pope Francis ordered the 88-year-old removed from public ministry on 20 June after a church panel determined that allegations he sexually abused a teenager in New York more than 40 years ago were “credible and substantiated”.

The former altar boy alleged that McCarrick, then a priest, fondled him during preparations for Christmas mass at St Patrick’s Cathedral in 1971 and 1972.

Since then, another man identified only as James has come forward, saying that McCarrick first exposed himself to him when he was 11 and then engaged in a sexually abusive relationship with him for the next 20 years. McCarrick has denied the initial accusation but has not responded to the second one.

At the time of McCarrick’s June removal, the New Jersey archdioceses of Newark and Metuchen revealed that they had received three complaints from adults alleging misconduct and harassment by McCarrick and had settled two of them.

Pope Francis then accepted McCarrick’s resignation on 28 July, effectively stripping him of his cardinal’s title, and ordered him to live a lifetime of penance and prayer pending the outcome of a canonical trial.