The Voices of Faith group said the former head of state was one of two names not approved after a list of attendees was sent to a senior cleric in the Holy See.
It is reported that Ms McAleese was blocked from speaking at an international conference on women’s rights by Dublin-born Cardinal Kevin Farrell.
Dr Martin said he first heard a decision had been made to exclude the former president from the Voices of the Faith conference from Ms McAleese herself.
“Neither Archbishop Martin nor his offices were consulted by the Vatican in relation to this matter,” a statement from the Archdiocese of Dublin read.
“Archbishop Martin has consistently noted that World Meeting of Families, due to take place in Dublin later this year will be an inclusive event, open to all families and family members,” it added.
The Why Women Matter conference, in its fifth year, is the only event linked to International Women’s Day (IWD) ever held at the Vatican.
A spokeswoman for the group said they still had no explanation why Ms McAleese was not cleared to take part. It is understood Ms McAleese has written to the Pope on the issue.
Voices of Faith sent a list of names of speakers and attendees for its March 8 conference and two names were excluded in a list sent back — Ms McAleese and Ssenfuka Juanita Warry, who runs a non-profit organisation in Uganda, where being identified as gay or lesbian can be life-threatening.
It is not unusual for a senior Vatican official to vet a list of attendees and speakers for conferences.
Voices of Faith has decided to move the conference from the Casina Pio in the Holy See to the Jesuit Curia in Rome, outside the Vatican. Ms McAleese was initially asked to take part in a panel discussion but has since been asked to be the keynote speaker at the conference entitled ‘Why Women Matter’.
The Vatican press office, the Catholic Communications office in Ireland, and Cardinal Farrell, the Prefect of the Vatican Dicastery for Laity, the Family and Life, did not respond to requests for comment.