Taoiseach Micheál Martin has demanded a review of an incident in which a solicitor was told to remove her bra to gain entry to a prison for a meeting with a client.
Details of the incident, first reported by the, have sparked further complaints from women who were subjected to similar experiences while visiting Irish prisons.
There are growing concerns the practice is widespread.
The Dáil heard details of the solicitor being forced to remove her bra in order to attend an urgent meeting with her client in Cloverhill Prison.
The woman said she was humiliated and traumatised by the episode which took place in front of four male guards and a male senior counsel.
The Taoiseach described it as "quite shocking" and "unacceptable" and said he would be seeking answers to find out why it happened.
"It is unacceptable, and should not have happened," said Mr Martin.
The Irish Prison Service (IPS) said it is not policy to request the removal of undergarments in order to gain admittance to a prison.
"The Irish Prison Service does not condone behaviour contrary to our standards of courtesy which may put at risk the rights of people to be treated with dignity and respect," a statement said.
Listed search procedures include a walk-through metal detector, handheld metal detector, narcotic swabbing, x-ray of outer clothing and bags, and canine drug detection. Removal of bras because of metal wiring is not listed.
Thehas found the practice is widespread and numerous partners and mothers of prisoners have detailed their experiences.
- One woman said she keeps two sports bras to visit her son "to avoid the humiliation";
- A number of women in the legal profession have said they had either been asked about their underwear by male guards or instructed to remove it;
- A solicitor said a male guard pushed a metal detector wand beneath her bra strap and "snapped it" back, telling her the bra "was the problem".
A female prison guard who has worked in a number of Irish prisons said she "wasn't surprised" by the revelations.
"I've seen it a million times," she said.
"There's a terrible undercurrent of sexism in the prison club. They're not all the same, but it is rife.
"I've seen mothers of prisoners come in and have to take their underwear off — people they think they can bully.
Minister of State Hildegarde Naughton, who has responsibility for prisons, has now sought a report, with detailed timelines, from the Director-General of the Irish Prison Service.
The Department of Justice said the Prison Service is currently reviewing all operating procedures and its security screening, which now includes a dignity at work element.
"Minister Naughton awaits the outcome of these reviews, which she has been told are being finalised, and completion of the report she has requested from the IPS on this matter," a spokesman said.
"When she receives these documents, Minister Naughton will assess what further action may be required."
The statement added that Ms Naughton will "of course" consider any request for a meeting with the woman involved.
Sinn Féin leader Mary Lou McDonald said the incident warrants a wider review of prison culture and practices to ensure that this type of "degrading treatment of any woman never happens again."