Former junior finance minister Brian Hayes says that social media speculation over who his guests were at the Oireachtas Golf Society dinner is "all made up".
Mr Hayes, now the head of banking group the Banking and Payments Federation of Ireland (BPFI), attended the event last week with three guests, something he has said was "a mistake".
However, he says that his guests, listed on the event's seating plan, were school friends and not directors of a vulture fund, a rumour which has spread on social media.
"They have no involvement in banking/financial services. I’ve seen the social media claims about vulture funds etc and it’s all made up. They are personal friends of mine for over 30 years.
"On lobbying - I was invited as a former member and attended in a private capacity while on holiday. I did not lobby anyone about anything."
Mr Hayes has said that he would not be standing down from his role, saying that he is "a private citizen".
Former Labour Party Senator Lorraine Higgins, who is now the CEO of Digital Business Ireland, a representative body for e-commerce and online businesses, was also at the event. She did not answer queries as to whether her attendance was registered under the Lobbying Act or whether she had attended in a private capacity.
Ms Higgins has yet to make any statement on her attendance at the event.
Meanwhile, the investigation into the attendance at the event by Supreme Court judge and former Attorney General Seamus Woulfe is expected to be completed within weeks.
Chief Justice Frank Clarke has tasked former Supreme Court judge Susan Denham to investigate whether Mr Justice Woulfe should have accepted the invitation to dinner., as well as whether he should have left the hotel "in the light of the situation prevailing".
Sources say that the report is expected to be ready before the beginning of the new legal year in early October.