Data Protection Commissioner Billy Hawkes has said it is not unusual for intelligence services to have access to data for legitimate reasons.
It was reported last week that US security agencies have been gathering millions of phone records and tapping into the personal data of many of the world's biggest internet companies.
Speaking to RTÉ's Morning Ireland, Mr Hawkes said that while he was concerned there may be abuses of power by those with access to data, he did not regard last week's revelations as "new".
Mr Hawkes said that the concern would be of abuse of a power that was given for a legitimate reason.
He said: "I think it is nothing new that there would be access to data by intelligence services to this data if it was required for legitimate reasons."
Mr Hawkes said that the issue was not whether agencies had access to people's data, but whether "appropriate safeguards" were in place to stop abuses of this access.
He said the activities of security agencies largely went beyond the aims and the remit of data protection laws.
Mr Hawkes was referring to revelations that a former CIA technical worker Edward Snowden leaked US surveillance programmes.
Mr Snowden released information that US agencies gathered millions of phone records and monitored internet data.
Mr Hawkes said: "The type of exercise here [in Ireland] goes beyond what data protection law is designed for, which is the normal world which is not the world of intelligence and security."
He said data protection law is designed to protect people against day-to-day activities.
Mr Hawkes said it is to ensure that banks or supermarkets do not leak information about a person and he said people can be reasonably secure that their information is "okay there".
The commissioner confirmed that all large internet companies based in Ireland have denied voluntarily giving out information.
He said his office carried out an investigation into Facebook Ireland and found it to have "very strict" procedures for giving access to law and enforcement agencies.
Elsewhere, Mr Snowden said he acted out of conscience to protect "basic liberties for people around the world".
The 29-year-old told the Guardian newspaper that he had thought long and hard before publicising details of an NSA programme code-named PRISM.
He said he had done so because he felt the US was building an unaccountable and secret espionage machine that spied on every US citizen.
His whereabouts are not known, but staff at a luxury hotel in Hong Kong told Reuters that Mr Snowden had checked out at noon local time.