A Dublin hospital that helps people with mental health issues has confirmed that it has received a complaint about Al Porter.
It follows a reported allegation in the Sunday Times about inappropriate behavior by the comedian during a visit to St Patrick's Mental Health Services with a charity.
At the time, St Patrick's Mental Health Services said that "no allegations, complaints or concerns had been made" about the former Today FM presenter, and encouraged the reporting of any such allegations.
In a statement this evening, the organisation said that "since issuing that press release, SPMHS has received such a complaint."
"The organisation is currently investigating the complaint in line with its policies and procedures."
Following a number of claims about his conduct at the weekend, Al Porter resigned from his lunchtime show on Today FM and issued a statement in which he said he "sincerely apologise to anyone I may have genuinely offended."
Al Porter's full statement:
"I have been completely taken aback by reports in the media and on the social networks over the weekend, and by the scale and tone of the vitriol. While my conduct, which had been in keeping with my flamboyant and outrageous public persona may be regarded as offensive and unacceptable by many people, I at no time intended to upset anyone.
"Up until now, I had been unaware of these complaints or the impact of my conduct and I am truly sorry for any distress I may have caused in what I had regarded as light-hearted and good-natured circumstances.
"Although, on legal advice, I cannot comment on specific allegations at the present time, I nonetheless sincerely apologise to anyone I may have genuinely offended.
"I am very grateful to Today FM, the Olympia Panto and TV3 for the space and time I’ve been granted to deal with the situation. I have however come to the personal decision that I need time away from the spotlight after decades in the entertainment industry. I have informed Today FM that I am resigning from the station with immediate effect.
"To my family, colleagues, friends and fans I thank you for your many, many messages of support."