The State spent more than €250,000 on a specially chartered flight to deport 13 foreign nationals to China earlier this year.
The deportees, 11 men and two women, were removed from the State on February 21st.
The overall amount breaks down to a cost of over €20,000 per person.
The flight from Dublin included two fuel stopovers in Leipzig, Germany, and Tashkent, Uzbekistan. Previous attempts to remove the deportees on a commercial flight had been frustrated by violent and disruptive behaviour.
Some of the deportees came to Ireland on student visas but failed to attend courses.
Four of the 13 had criminal convictions. One man was involved in a street fight on O'Connell Street, Dublin, in July 2002, between members of the Chinese community that caused the death of a Chinese national. Another deportee had been jailed for his part in a false imprisonment and extortion case.
About 30 gardaí travelled with the deportees to Beijing.
The Department of Justice said deportation charters must be arranged well in advance and so it is not possible to anticipate the number of deportees that would be on any one flight.
The department said that the Irish Naturalisation and Immigration Service has to make contact with a service provider to agree a contract on the availability of a suitable aircraft and crew on the preferred deportation dates.
It said that regardless of the number of deportees on board the charter flight, the cost would remain at the agreed contracted price.
In the first five months of 2006, the State has spent € 721,444 on chartering flights for deportations. A total of 270 people who were residing illegally in the State have been removed so far this year.
One person was flown to Spain in January, at a cost of € 43,300. This flight was chartered to transfer a particularly difficult and violent person in accordance with the provisions of the Dublin II Regulation, which allows for another EU state to process an application if the claim for asylum was made there first.
Department of Justice figures show that over € 6.1 million was spent on scheduled and chartered flights between 2000 and 2005.
Costs for chartered flights were released to the Dáil in response to a parliamentary question submitted by Fianna Fáil TD Ivor Callely.