The District of Columbia has opened a civil investigation into whether the Archdiocese of Washington covered up sexual abuse of minors by Catholic clergy, the DC attorney general told local elected officials on Tuesday.

At least 13 states and the District of Columbia are conducting civil or criminal investigations into allegations of sexual misconduct or cover-up in the Catholic Church, Attorney General Karl Racine said, according to his office.

The Roman Catholic Church has been enmeshed in a sex abuse scandal that has enveloped clergy in a number of countries, including the United States, Germany, Chile, Australia and Ireland. In August, Pope Francis issued an unprecedented letter to all Catholics vowing that there would be no more cover ups of sexual abuse by clergy.

The former archbishop of Washington, Theodore McCarrick, 88, resigned from the College of Cardinals in July. He has denied allegations that he sexually abused a 16-year-old boy in the early 1970s when he was a priest in New York. Church officials have deemed the accusations credible.

Racine told Washington officials that nonprofits like the Washington archdiocese are 'required to work for a public purpose' and that 'if they are in fact covering up child sex abuse, that is clearly not in the public interest'.

Felonies in Washington are handled by federal prosecutors, who have not announced any investigations into clergy abuse in the archdiocese.

The US attorney's office for the District of Columbia said on Monday that it had created a telephone hotline and an email address for people to report allegations of clergy abuse. Federal prosecutors will check into accusations and determine whether criminal charges should be filed, the office said.

The archdiocese said in a statement that last month its attorneys met with Racine.

Kim Viti Fiorentino, attorney and chancellor for the archdiocese, said it 'remains committed to a collaborative and transparent review process because there is not now, and has not been for decades, any problem of abuse of minors by clergy of the Archdiocese of Washington'.

Earlier this month, the archdiocese released the names of 28 priests it said had been credibly accused of child sex abuse since its founding in 1948. It said there were no priests in active ministry in the Archdiocese of Washington who have been subject to credible allegations of abuse.