Sinn Féin has called on the Government to clarify whether a series of flights carrying military equipment, including rifles and explosives, had sought and were given permission to land at Shannon airport.
The party obtained details relating to seven flights involving one cargo aircraft which passed through Shannon airport during September and October.
Last night the Department of Transport and the Department of Foreign Affairs were checking records for the detailed instances, but sources indicated that permission for flights of this nature were sought and approved during this period.
It is legal under Irish law for third countries to transport military goods through Ireland once it has received permission from the Irish authorities.
According to manifests provided to Sinn Féin, a flight operated by a Bulgaria-based operator Vega Airlines, landed in Shannon on October 8th.
Its manifest claimed it was carrying six tonnes of "ammunition, explosives, inert equipment" from the US Office of Anti-terrorism Assistance, and was destined for the US embassy in Indonesia, where it was to be used for anti-terrorist training.
A series of other flights involving the same plane on October 15th, 17th, 21st and 28th also landed at Shannon, carrying unidentified equipment, destined for a Bulgarian airport frequently used for military purposes.
The 2.6 tonnes of goods transported on October 21st is described in the documentation as "dangerous goods" while a cargo of M16 rifles were transported on October 8th.
Sinn Féin TD Aengus Ó Snodaigh, who obtained the details, said the transfer of weapons to Indonesia was questionable as there had been an arms embargo against military exports in recent years over human rights abuses in the country. A spokesman for the Department of Foreign Affairs said no embargo existed in relation to Indonesia.
Last night the Labour Party reiterated calls for an independent investigation into rendition flights, and said Sunday's incident of a US marine prisoner being transported through Shannon without the proper notification of Irish authorities added further concerns.
Amnesty International has called on the Government to regain control over use by US military aircraft of Irish air space and territory. Colm Ó Cuanacháin, secretary general of Amnesty's Irish section, said that Ireland's "skies and airports are excessively open to US flights".