Coimisiún na Meán (CnaM) has begun its first formal investigation under Ireland's Online Safety Code.
The watchdog is investigating whether social-media platform X's age-assurance mechanisms and parental-control system are effective enough to prevent children from accessing adult-only content or videos depicting extreme violence or cruelty.
CnaM said that the probe followed reviews by a supervisory team that led to concerns about "the potential ineffective implementation of age-assurance mechanisms".
Under the code, age assurance is required on X to ensure that children do not see videos depicting pornography, extreme violence, or acts of cruelty on the platform.
CnaM added that, under the code, age assurance based solely on self-declaration was not considered effective.
The code also requires parental-control systems due to the presence of adult-only content on X and the fact that children under the age of 16 are allowed to use its service.
"A concern exists that the parental controls put in place by X may not be effective, do not have minimum requirements, are hard to locate, and are not brought to the attention of new users at sign-up stage, as required by the code," it stated.
CnaM digital-services commissioner John Evans said that children had a fundamental right to participate in society – including the digital world – and to be protected from harm, abuse, and exploitation online.
It is also involved in four joint investigations that have been opened by the European Commission.
The investigation that started yesterday (8 September) will be conducted under part 8B of the Broadcasting Act 2009, as amended.
If a platform is found in violation of the Online Safety Code, CnaM can apply an administrative financial sanction – including a fine of up to 10% of relevant annual turnover, or €20 million, whichever is greater.