TDs were severely criticised yesterday for inviting an "evil and destructive" religious cult to appear before a parliamentary committee.
The Church of Scientology's address to the Oireachtas education committee sparked outrage from families who claim their relatives were manipulated by the "mind control" cult.
The church proposed that illiterate prisoners should not be released until they have learned to read and write.
The committee was accused of legitimising the organisation by affording it an official status before a State body.
Set up by the deceased US author L Ron Hubbard, the controversial church's members include Hollywood stars Tom Cruise and John Travolta.
It has been described as "evil, deceptive, deceitful" by Diarmuid Fortune, whose family has campaigned for a decade to get their brother from the cult.
"It is absolutely disgraceful that an organisation like Scientology can be invited in to an Oireachtas committee.
"They are a destructive cult. It is about mind control. It is horrendous how they treat people. They put you into a mental straitjacket," said Mr Fortune.
"They will use all that publicity. They will put angles on it that the Government has endorsed them," he added.
The country's only cult watchdog also accused the committee of giving a stamp of approval to the Church of Scientology.
Dialogue Ireland director Mike Garde said the cult had been found guilty of manipulation in court cases in Europe.
Its tactics were constantly under scrutiny.
In Germany, members of the church are banned from holding jobs in the public sector, he said. "That is how dangerous it is regarded in the German state," he said.
In its submission to the hearings on adult literacy, the church's head in Ireland, Gerard Ryan, said prisoners should not be released until they had learned to read and write. Prisoners could be released early if they attained a certain literacy standard.
Although members of the committee dismissed some of the suggestions as "daft", TDs defended their decision to invite the church to appear.
Education committee vice-chairperson, Labour's Jan O'Sullivan, said the committee did not want to censor the views of the church after it made a submission on adult literacy.
The committee was obliged to read and listen to its views. She did not know anything about the organisation.
Defending the church's position, Mr Ryan strongly refuted the accusations made by the families of its members and denied it was involved in manipulation.
The Church of Scientology was involved in a high profile court case three years ago, when a Dublin woman claimed she was controlled by the cult. The High Court action was settled out of court.