Tánaiste Michael McDowell has insisted that the Government accepts American assurances that there is no illegal transport of prisoners through Irish airports.
Mr McDowell said Taoiseach Bertie Ahern, Minister for Foreign Affairs Dermot Ahern and himself had been personally assured at the highest level by the US authorities, through its Secretary of State, and at diplomatic level, that there had never been an instance of a rendition flight going through Irish air space.
"I would like to add that experts who have examined this have stated that, in their view, it would be highly improbable that the United States would ever have selected Shannon as a place for rendition flights. And I accept that view."
Mr McDowell said members of the Garda were fully entitled to search any aircraft if they had a reasonable belief that a crime was being committed on board.
"It would be a crime to detain, against their will, any person on a flight, other than on foot of an extradition treaty which is not relevant to this case."
The Tánaiste was replying to Sinn Féin Dáil leader Caoimhghín Ó Caoláin.
Mr Ó Caoláin asked if the Government intended continuing to ignore the use of Shannon airport by US military and CIA-sponsored aircraft in the furtherance of their war in Iraq.
"Will the Government continue to facilitate the use of this facility which clearly is in clear and flagrant conflict with our stated position relating to neutrality?"
Mr Ó Caoláin added that an EU committee had found the State had hosted 147 secret CIA flights, the third highest number among EU states.
Mr McDowell said: "If I were to reject the solemn, unequivocal word of three senior officials of the United States administration relating to this, and to disbelieve them, it would be a very serious step indeed.
"If relations between Ireland and America were at such a low ebb that we could not believe members of the American administration on this issue, and that we were naive to believe them, then I believe a lot of rethinking would have to be done."
Addressing the Sinn Féin benches, Mr McDowell said: "You may ask this Government to regard the assurances received from the American administration as false. You may ask us to do that, but if you do, do not go knocking on the door to get into the White House on St Patrick's Day."
As Minister for Justice, he had repeatedly called on any person with credible evidence that Shannon was used for allegedly unlawful purposes, to share the information with the Garda authorities.
"I would remind the House that the president of the Human Rights Commission, Dr Maurice Manning, has said that there was no smoking gun. I would ask some of the members of the House to pay some attention to what he says instead of misquoting him and attempting to suggest that Ireland has been used for rendition flights. It has not."
Mr Ó Caoláin said that surely the Irish people, if not the world community, was entitled to be reassured on the issue. It would be in the interests of truth and right that occasional spot checks were carried out to give an indication that there was substance to the Tánaiste's belief.
