Minister for Sport John O'Donoghue has described as "scurrilous" claims by Labour leader Pat Rabbitte that he had links to a trainer involved in a doping incident in the greyhound racing board controversy.
Mr Rabbitte also claimed in a Dáil row that the Minister had reappointed to the greyhound board, a director banned from being a director of his own firm.
Mr O'Donoghue said: "Scurrilous, scurrilous, scurrilous."
The row follows a dispute at Bord na gCon over the sacking last week of its chief executive Aidan Tynan, who had earlier revealed unpublished details of a drug-testing hearing to the Minister.
The board and its chairman Paschal Taggart have insisted Mr Tynan's sacking followed difficulties between him and the board and was not the result of his revealing details of the hearing.
In the Dáil, the Labour leader said there were "extraordinary stories" circulating about Bord na gCon. "Every day there is a new piece of anonymous literature concerning matters that are allegedly going on there," he said.
"I have been in correspondence for more than a year with the Minister over his reappointment of a director who was disqualified from acting as a director of his own firm for very serious reasons. Yet the minister went ahead and reappointed him."
Mr Rabbitte added: "I believe the Minister might have some contact with one of the trainers who is involved in the doping incident and he appoints the chairman, initially to inquire into why the chief executive was sacked by the chairman."
"Does the deputy know he is being scurrilous?" asked Mr O'Donoghue. "Scurrilous, scurrilous, scurrilous."
Mr Rabbitte asked Tánaiste Mary Harney, who was taking the Order of Business, about the terms of reference of former department of justice general secretary Tim Dalton for the inquiry "that has been dragged out of the Minister for Arts, Sport and Tourism, Deputy O'Donoghue".
He asked if Mr Dalton "is inquiring only into the circumstances of the dismissal of the chief executive or if his terms of reference involve an investigation into the various matters coming into the public domain about Bord na gCon".
Ms Harney said she had also "had a good deal of anonymous correspondence as regards dogs, and I must admit I do not know much about them".
She had taken a call from "a leading journalist last Friday night asking whether I had a dog, which I took to be a joke". She said there were "serious issues involved" and Mr Dalton would "conduct a full inquiry".
