The warning comes weeks before Mr Justice John Murray is due to report to government on his independent review of the legislation.
In an assessment of the same legislation, Shane Kilcommins and Eimear Spain of the School of Law at University of Limerick said the way that the law — specifically a 2011 Act — has been interpreted as giving powers to GSOC to access phone records “raises a number of concerns”.
They also said years went by without any oversight of GSOC’s use of those powers.
Under the 2011 act, a judge must be appointed each year to review the use of the powers by all State agencies so empowered.
The act says the judge should “ascertain whether the Garda Síochána, the Permanent Defence Forces, and the Revenue Commissioners are complying” with the law but does not mention GSOC.
In 2011, 2012, and 2013, the designated judges referenced only the gardaí, Revenue Commissioners, and the Defence Forces in their reports and made no mention of carrying out the same scrutiny in relation to GSOC.
“It is only in the 2014 report that the designated judge mentions for the first time that he ‘attended the Office of An Garda Síochána Ombudsman Commission’,”said Prof Kilcommins and Dr Spain.
“The legitimate question this begs is whether GSOC was using its perceived powers under the 2011 Act prior to 2014 and, if so, what independent oversight was in place in that period.
“If it was using its powers under the act between 2011 and 2014, but was not subject to oversight, does this have consequences for information gathered by GSOC during that period?”
Prof Kilcommins and Dr Spain published their assessment on the Human Rights in Ireland blog. They began work on it following the controversy that erupted in January over the revelation that GSOC was trawling journalists’ phone records as part of investigations into complaints about Garda leaks to the media.
Justice Minister Frances Fitzgerald has said GSOC’s powers come from a combination of the Data Retention Act of 2011 which gives such powers to the gardaí, and an earlier 2005 act that established GSOC and provided that GSOC officers would have most of the same powers of investigation as gardaí.
Prof Kilcommins and Dr Spain concluded that such “catch-all provisions” were contrary to the principle that “the legislature should expressly provide the agency with the power” and suggested it would not survive a challenge in the European Court of Human Rights.