The republican leader has faced calls to explain how Liam Adams chaired a branch of Sinn Fein in west Belfast in 2000 – three years after he claimed he had him expelled from party ranks.
"I don't know every member of the party in west Belfast," he said yesterday. "I am also a very busy activist – a lot of this happened at a time of intense hyperactivity – but I didn't know."
Liam Adams is currently on the run from the police on charges that he sexually abused his daughter Aine Tyrell in the 1970s and 1980s.
His high-profile elder brother has had to defend claims he did not do enough to alert the authorities when he found out his estranged brother was working in youth groups in west Belfast and the Irish Republic over the last 15 years.
But the controversy took another twist yesterday when Sinn Fein revealed that three years later Liam Adams became involved again with the party in Andersonstown, which is Gerry Adams's west Belfast constituency.
While he did not re-apply to be a member, he did chair a branch in Andersonstown for a period, party chairman Declan Kearney explained.
The revelation has thrust the focus back on Gerry Adams, with queries as to how he could not have known about his brother's involvement.
Currently engaged in high-level political talks aimed at achieving the devolution of policing powers to Stormont, Gerry Adams restated his position during a break from negotiations.
"I got my brother Liam to leave Sinn Fein in County Louth," he said.
"He later, unbeknown to me, rejoined the party in west Belfast. Had I known that that was the case, and I didn't know that until Thursday, when Declan (Kearney] gave us his report, I would have moved to get him to leave the party there also."
He added: "My clear view is that my brother Liam should not have been a member of the party."