Amnesty International has said that more than 80 flights operated by the Central Intelligence Agency passed through Irish airports in the last five years.
In a new report, Amnesty said it had tracked 1,000 flights made by four civilian aircraft which it claims were chartered by the CIA.
Amnesty said the planes passed through Shannon on 78 occasions since 2001.
They used Dublin Airport three times in the same period and passed through Belfast and Derry airports five times.