Attorney General John Larkin is to review a decision not to prosecute Sinn Féin leader Gerry Adams for allegedly withholding information on his brother.
Liam Adams was convicted last week of raping and abusing his daughter, Áine, over a six-year period in the 1970s.
Director of Public Prosecutions Barra McGrory asked for a review of the decision not to prosecute Gerry Adams.
Gerry Adams testified at Liam Adams' first trial which collapsed for legal reasons.
Gerry Adams, the TD for Louth and a former West Belfast MP, did not give evidence at the second trial.
Liam Adams has yet to be sentenced.
Responding to the latest development, Gerry Adams said: "I have no comment to make in respect of this decision.
"This is a matter for the legal authorities, although I note that the PPS (Public Prosecution Service) has said it has 'confidence in the evidential decisions taken' previously in this case.
"However, it is clear that there are some politicians and elements in the media who have decided to use this issue for opportunistic and party political reasons, and who seek to politicise what is, at its heart, a family tragedy.
"The fact is that I co-operated fully with the PSNI, the PPS and the prosecution lawyers throughout this case."
Paul Givan, chairman of Stormont's justice committee, welcomed DPP Barra McGrory's decision to review the case.
'Question of confidence'
The DUP Lagan Valley MLA said: "It is difficult to understand why the PPS did not ask the police to follow clear lines of inquiry and investigate Gerry Adams about the potential criminal offence of withholding information about sexual abuse.
"The PPS has the power, which it uses frequently, to ask for people to be investigated by the police and establish if there is sufficient evidence to bring forward a prosecution, but on this occasion it did not ask for any further information.
"There is a clear question of confidence in the PPS in respect of its handling of this case. It is critical that whilst everyone is equal before the law they are equally subject to the law. The public must have confidence in the criminal justice system to act impartially at all times."
At the first trial in April, Gerry Adams said his brother admitted that he had sexually abused Áine Adams. He made the admission during a "walk in the rain" in Dundalk, County Louth, in 2000, Gerry Adams said.
Gerry Adams said that, during the encounter in Dundalk, his brother, while admitting molestation or sexual interference or assault, did not admit rape.
The Sinn Féin president made his first report to the police about the allegations in 2007, shortly after his party voted to accept the Police Service of Northern Ireland.
In 2009, Gerry Adams made a second statement to police, telling officers that his brother Liam had confessed to him nine years earlier, in 2000, that he had sexually abused his daughter Áine.
In 2007, while Gerry Adams was giving the police statement in which he did not mention his brother's confession, Mr McGrory was the Sinn Féin leader's solicitor.
He was appointed Northern Ireland's director of public prosecutions in November 2011, a month after the decision not to prosecute Gerry Adams for withholding information was taken.
The Public Prosecution Service said on taking up the job, Mr McGrory had flagged up his prior involvement in the case and had no involvement in any prosecution decisions around it.
A spokesman for the DPP said that, as Mr McGrory was now the director of public prosecutions for Northern Ireland, it would not be appropriate for him to comment on any communication he had with a former client.