Sinn Fein deputy leader Mary Lou McDonald moved swiftly to disassociate herself from Jonathan Dowdall after a court heard he boasted to his victim he was a friend of both her and Gerry Adams.
The Dublin TD said the details of Dowdall's attack on his victim Alexander Hurley were "truly shocking".
She said former Sinn Fein councillor Dowdall had left the party some years ago and he had supported one of her political opponents in the Dublin Central constituency. A spokesman for Sinn Fein leader Gerry Adams said he would not be making a statement.
Dowdall, and his father Patrick, both pleaded guilty to falsely imprisoning Mr Hurley and threatening to kill him during the ordeal at their home on the Navan Road more than two years ago.
The Special Criminal Court heard yesterday that Jonathan Dowdall told his victim he was a "stupid dumb f**k to mess with the head of the IRA."
The victim said Jonathan Dowdall told him he was a friend of Mr Adams and Ms McDonald.
He was told to get out of Dublin.
"I welcome the conviction of Jonathan Dowdall in court today," Ms McDonald said, speaking after evidence was made public.
"The details of the attack perpetrated by him are deeply shocking. I hope the sentence delivered by the court reflects the seriousness of the offence and the trauma endured by his victim."
She said Dowdall was not a Sinn Fein member.
"Jonathan Dowdall left Sinn Fein some years ago," she added.
"He subsequently worked with, and supported, a political opponent of Sinn Fein in the Dublin Central constituency."
Dowdall had been a public supporter of Ms McDonald while he was a Sinn Fein councillor.
He later resigned, claiming that he had suffered bullying by some members of the party.
Sinn Fein TD Aengus O'Snodaigh later rejected his claim and said the party had "robust mechanisms" to deal with bullying claims. Another Sinn Fein member, Gaye Fagan, was later co-opted by the party to fill Dowdall's council seat.
Dublin Sinn Fein TD Louise O'Reilly said Dowdall "hasn't been a member of Sinn Fein for a very, very long time".
"My understanding is he wasn't a member of Sinn Fein when the incident that's referred to in the court case took place," she said.