Sinn Féin leader Gerry Adams says he believes Paudie McGahon was raped but does not know if he was brought before a kangaroo court, as Mr McGahon has alleged.

Mr Adams said he regretted very much what happened to Mr McGahon and said "the perpetrator of his abuse" should face due process. Mr McGahon, from Co Louth, featured in a BBC Spotlight programme on Tuesday night.

"I believe he was raped, yes," Mr Adams said in the course of an interview on RTÉ Radio's Morning Ireland programme on Wednesday. Asked if be believed Mr McGahon's allegation that he was subjected to internal IRA inquiries, Mr Adams said: "I don't know".

Mr Adams said a Garda investigation was underway. “The fact is the IRA should not have been near any of these cases whatsoever. That was inappropriate,” he said.

The Sinn Féin leader said he regretted very much what had happened to Mr McGahon.

Mr Adams said he first knew about Mr McGahon’s claims around 2009 when the young man went to meet with his then local Sinn Féin TD Arthur Morgan.

Quoting from a letter he said Mr Morgan wrote to Mr McGahon, Mr Adams said Mr Morgan had advised Mr McGahon to go to the police.

Asked why he himself did not approach the gardaí, Mr Adams said Mr McGahon was an adult and he did not want to go to the police. He repeatedly said Mr McGahon was an adult.

Mr Adams said he was a law maker, not a law enforcer. He said his party had strong child protection rules.

He said the “perpetrator” was not acting in his name and brought shame to the Republican “cause”. Mr Adams said he did not know where the man was. If he did he would inform the Garda.

Mr Adams accused Fianna Fáil leader Micheál Martin and others of attempting to “politicise” the matter, adding that he thought it was “despicable”.