Justice minister Alan Shatter has requested a report into the alleged bugging of the Garda Ombudsman.
It follows claims in a Sunday newspaper that the police watchdog was under high-tech surveillance.
The espionage was uncovered last year after the office hired a British security consultancy to investigate whether its headquarters in Abbey Street, Dublin, and internal communications system were bugged, the Sunday Times reported.
A spokesman for the justice minister said: "Minister Shatter has requested a report from the Ombudsman and will not be making a comment until he has received and considered that."
The Garda Siochana Ombudsman Commission (GSOC) is responsible for receiving and dealing with all complaints made by members of the public concerning the conduct of members of the force.
The Ombudsman could not be contacted for comment.
Fianna Fail justice spokesman, Niall Collins, said: "GSOC performs an important role in oversight of the Gardai, with access to very sensitive material; indeed, in Fianna Fail we have been making the case for extending and deepening the powers available to the Commission.
"The idea that someone or some organisation is engaged in covertly monitoring the Ombudsman is deeply unsettling and risks undermining public confidence. The Minister needs to come forward and explain whether he has spoken to the Ombudsman and whether he was aware of this surveillance.
"If he was, he needs to explain why on earth this was going on? If he wasn't we need to get answers very quickly on who is responsible."