Labour TD Brendan Howlin has confirmed that Martin Giblin, the McBreartys' family lawyer, was the source of his information which led to the setting up of the Morris Tribunal.
Mr Howlin says the Dublin-based lawyer, whom he spoke to yesterday, has now released him from any obligation to continue protecting him.
However, he says that Mr Giblin revealed his identity to the Morris Tribunal two years ago and this was also passed onto the gardaí.
Mr Howlin is now calling on the tribunal to explain why it has pursued him through the courts.
The Wexford Labour TD says the tribunal has attempted to undo the principle of the confidentiality of information passed onto public representatives and it must explain this.
The mystery stretches back more than five years to a phone call Mr Howlin received in June 2000.
That information led to the setting up of the Morris Tribunal into allegations of garda corruption in Co Donegal.
The tribunal has persisted in trying to find out the source of Mr Howlin's information, resulting in a Supreme Court judgement last month that he must hand over his phone records.
