Just two days later, Gerry Adams said in a blog post that the IRA had "shot" alleged sex offenders or expelled them.
And then, a month later he told Irish state broadcaster RTÉ that the names of alleged republican sex abusers had been posted anonymously through his letterbox in Belfast.
A Sinn Féin party insider told Spotlight that the party did investigate abuse allegations.
The Sinn Féin insider spoke to the programme on the basis of anonymity and said: "Allegations of abuse are dealt with carefully now, but past allegations of abuse are more likely to have been handled by the party locally.
"If there is a case about allegations of abuse anywhere it goes up the line.
"Leaving aside the justice angle, all of these things have potential serious political repercussions. So the idea that it would not go up the line is not credible.
"It is not credible for leadership to say they didn't know of other cases. Anything significant and anything of any substance would be known by leadership people."
A separate republican source told Spotlight that senior members of Sinn Féin were involved in investigating allegations of abuse by republicans.
Spotlight asked Sinn Féin: "Were senior members of the party ever involved in investigating allegations of abuse by republicans?"
In response the party said: "Sinn Féin does not conduct any inquiries into allegations of abuse. That is the role of the police North and South."
Spotlight asked for clarification on whether it had ever happened, but the party did not respond on that point.
The Friday following the Maíria Cahill BBC Spotlight programme, a Sinn Féin spokesperson told a Dublin radio station that "Gerry Adams was not aware of any other cases of abuse".