Gerry Adams has denied that he only went to police nine years after allegations of child abuse emerged against his younger brother to save his political career, as he gave evidence in court.
The trial of Liam Adams heard that the Sinn Fein president did not tell police until 2009 that he had allegedly confessed to the abuse as they walked together in Dundalk in 2000.
During cross-examination, defence barrister Eilis McDermott QC asked why Gerry Adams had not told detectives about the alleged admission until a month before a television programme relating to the child abuse claims was to be aired.
"I am suggesting that the reason you made this statement was to save your political skin," said Ms McDermott.
Gerry Adams replied: "If I had been interested in saving my political skin I would not have got involved with the process at the beginning. I tried to fulfil my responsibility as an uncle to a young woman I am very fond of. This is above politics and saving my political skin had no consideration in any of these matters."
The court heard that Gerry Adams, on the advice of his solicitor, made two separate statements to police in 2007 and 2009. "The statement came in two parts - two months and four months apart - and just one month before you were interviewed by a television journalist," said Ms McDermott.
Mr Adams answered: "That may be chronologically right but to link one to the other is absolutely and totally wrong."
Liam Adams from Bearnagh Drive in west Belfast is standing trial at Belfast Crown Court accused of 10 counts of child sex abuse including rape, indecent assault and gross indecency. He has denied all the charges against him.
Aine Adams, 40, claims she was abused from the age of four until about nine-years-old, between 1977 and 1983.
Gerry Adams, who was sworn in as a prosecution witness, gave evidence to the jury of six men and six women for almost four hours. He repeatedly denied he had wanted to avoid claims that he withheld information about child sex abuse.