Marie Collins is an Irish survivor of clerical sexual abuse who in 2014 was appointed to a special Vatican commission created by Pope Francis to protect minors.
She was 13 years old when she was molested by a priest.
She has now resigned, saying that she could not accept the obstruction she encountered from some of the Roman Catholic Church's most senior clerics.
(Photo: Marie Collins attends a press conference at the Vatican. Credit: Tiziana Fabi/AFP/Getty Images)