St Patrick's Mental Health Services has confirmed it has received an official complaint in relation to Al Porter.
The Hospital is now investigating the complaint against the comedian and former Today FM presenter.
Last weekend, allegations broke of inappropriate behaviour made against Al Porter while engaging in an awareness-raising event at St Patrick's Mental Health Services.
In a press statement, St Patrick's said that no allegations, complaints or concerns had been made to them by service users or staff in respect of Mr Porter, and encouraged people to come forward to Gardai.
Since issuing that press release, St Patrick's says it has now received a complaint.
The organisation says it is currently investigating it in line with its policies and procedures.
They say there will be no further statements until the investigation is complete.
Porter resigned from Today FM following allegations of inappropriate behaviour made on social media and in several newspapers.
In a statement released by the comedian, he said he "at no time intended to upset anyone" with his conduct.