Foreign law enforcement agencies will be allowed to tap Irish calls and emails under a new statutory instrument signed into law by Justice Minister, Frances Fitzgerald.
Companies who refuse to comply with an intercept order could be brought before a private court.
The Irish Times reports that the tapping can only be used in cases where an investigation is underway, and cannot be used at random.
The legislation took effect on Monday after being signed into law on November 26th.
Digital rights groups have expressed concern over the new legislation.
Solicitor Simon McGarr, who acts for the Digital Rights Ireland, says it is a worrying development:
It comes a week after it was claimed our high speed internet connections to the UK was being monitored.
Documents released by whistleblower Edward Snowden show that our main underwater links - which in effect connect us to the rest of the world - have been targeted by British intelligence.
It is reported the revelations were contained in documents leaked by National Security Agency (NSA) whistleblower Mr Snowden to a German media organisation.
A document called "Partner Cables" listed the cables that the British government communications headquarters (GCHQ) has accessed or sought to access. The commercial owners of the cables are identified by codenames.
They include one undersea cable, which extends from the Wexford coast to southern Wales.
Originally posted at 11.35am
