Dublin City Council shelled out almost €1,500 a day in consultancy fees to the whistleblower in the Iris Robinson affair.
The council paid Dr Selwyn Black over €30,500 to facilitate "a review of the Council's Staff Support Service in consultation with the Council's staff counsellors".
Dr Black hit the headlines as the whistleblower who revealed details of Iris Robinson's affair last December.
The wife of Northern Ireland's First Minister, Peter Robinson, Iris stepped down after it emerged that she had an affair with businessman Kirk McCambley who was aged 19 at the time.
Dr Black was the political advisor to Mrs Robinson and saved hundreds of texts sent to him by the ex-DUP MP.
They also showed how Iris secured £50,000 (€57,368) from developers Fred Fraser and Ken Campbell to set Kirk up in business at the Lock Keeper's Inn before demanding £5,000 (€5,736) be returned.
And it was revealed that Dr Black's company, Apheideo Associates, were awarded a £42,120 (€48,307) contract by Belfast City Council.
Dublin City Council has now confirmed that it paid €1,455 per day for the 21 days consultancy provided by Dr Black.
A spokesman said that Dr Black facilitated "a review of the Council's Staff Support Service in consultation with the Council's staff counsellors".
"The review was undertaken by the management and the Staff Support Counselling team to examine and ensure best practice in employee counselling and support provided to Dublin City Council staff," they said.
"Staff Support Service is a confidential service provided to any employee in Dublin City Council," they added.
"The council is not currently professionally engaged with Dr Selwyn Black or Apheideo Associates."
Dr Black's solicitor said that he did not wish to make comment about the contract with the city council in Dublin.
"Our client does not propose to say anything at present," his solicitor said.
Dr Black has also worked as a lecturer in counselling at the University of Ulster, where he carried out research with staff working with the victims of the 1998 Omagh bomb.
The psychiatrist started working for DUP MP Iris Robinson as a political adviser in January 2008.
His employee counselling and welfare support consultancy is currently involved in a research programme into work-related stress in conjunction with the Health and Safety Executive Northern Ireland.
He has also worked as Methodist minister in Dublin and in several countries as a military chaplain with the Royal Air Force.