The head of the Catholic Church in Ireland has resisted calls for his resignation after he confirmed he was present at a meeting where two teenagers abused by the paedophile priest were asked to take a vow of silence.
The then Fr Brady was a part-time secretary to the late Bishop Francis McKiernan when he interviewed the young victims who were made to sign the oath of secrecy.
"I will only resign if asked by the Holy Father", Cardinal Brady said on Monday.
"The pope is not in the habit of asking bishops to resign. In fact, in Canon law the pope doesn't really have the authority to force a bishop to resign", Michael Kelly, Deputy Editor of the Irish Catholic newspaper, told UTV Live Tonight.
"What the law says is if a bishop becomes unsuitable for office he is earnestly requested to resign. Therein lays the problem. The Pope can't really force a resignation, so it seems very unlikely at this stage that the pope will ask him to resign."
Cardinal Brady, who is being sued by one of the Smyth's victims in Dublin's High Court, has maintained there was no cover-up when he carried out his investigations 35 years ago.
"I did act and acted effectively in that inquiry to produce the grounds for removing Fr Smyth from ministry and specifically it was underlined he was not to hear confessions, and that was very important," the Catholic primate said.
But Mr Kelly told UTV the latest revelations about Cardinal Brady, whom he described as "a very competent canon lawyer at the time", will be "extremely damaging".
"We now know that he knew in 1975 that Brendan Smyth was abusing children and he didn't tell the civil authorities about that. I think that is going to play out very badly in Rome and the Vatican will be very annoyed about this."
Asked why he did not see it as a moral obligation to ensure the police were alerted, the Catholic primate said on Monday: "Yes, I knew that these were crimes, but I did not feel that it was my responsibility to denounce the actions of Brendan Smyth to the police."
He said he had helped gather evidence for the church to stop Smyth operating as a priest.
"Now I know with hindsight that I should have done more, but I thought at the time I was doing what I was required to do", he said.
Mr Kelly told UTV Live Tonight Cardinal Brady "handled the canonical side of it very well".
"Father Brendan Smyth was removed from ministry very, very quickly within three weeks.
"But he wasn't made to face up to his crimes to the civil authorities and as a result it was almost 20 years later before he was finally convicted and that was by the RUC, north of the border."
A victims' father, who wants only to be known as Seamus, told UTV: "The survivors would get a lot of hope out of the fact that (Cardinal Brady) is resigning and he owns up to the fact that he made a terrible mistake and that the welfare of the survivors and victims wasn't considered by him or anyone else".
"He did everything that was required from him within his position with the Catholic Church as he was a young priest and the hierarchy and the bishops pulled the strings and he danced accordingly", Seamus added.
"He was told to keep this quiet, to get those two children to sign a confidentiality clause and then walked away from it".
The Father Brendan Smyth case rocked the church and the Irish Government, which collapsed in 1994 over delays in granting his extradition to Northern Ireland to face sex abuse charges.
It was not until the broadcast of a UTV documentary in 1994 on Smyth's history of serial child sex abuse that the church admitted it had known about his paedophilia and had moved him around Ireland, Britain and the United States, where he was able to continue to abuse other children.
Amnesty International said the latest revelations underlined the need for a Northern Ireland inquiry into child abuse.
"Whatever happens about the future of Cardinal Brady, the Northern Ireland Executive has an urgent and overriding obligation to institute a thorough investigation of child abuse both inside and outside Church-run institutions within this jurisdiction", Patrick Corrigan, Northern Ireland Programme Director of Amnesty International, said.
Three months ago Cardinal Sean Brady insisted he would resign if his failure to act had allowed or meant any children were sexually abused by a paedophile priest.