A new report from Oxfam identifies Ireland as one of four European Union countries that would be blacklisted as a tax haven if the EU were to apply its own criteria to member states.
The EU is currently drafting a blacklist for tax havens, analysing 92 non-EU countries and jurisdictions against a set of three criteria, which include tax transparency and policies that facilitate large-scale profit-shifting.
However, this process excludes EU member states, meaning they will not be assessed.
Oxfam has applied the EU's own criteria to 92 countries worldwide, as well as to the 28 EU member states and, according to its analysis, at least 35 non-EU countries should be included in the EU tax haven blacklist.
Luxembourg, the Netherlands, and Malta also met the criteria for being listed as a tax haven.
In its report, Oxfam says Ireland fails to meet the second criterion on fair taxation and the facilitation of tax avoidance.
The report establishes that royalties sent out of Ireland were equivalent to 26% of the country's gross domestic product in 2015, which is more royalties than are sent out of the rest of the EU combined.
"As Ireland fails the EU's blacklisting criteria, it is clear that the Government has questions to answer with regard to its stated commitment to tackling tax avoidance," said Oxfam Ireland Chief Executive Jim Clarken.
"In the past, the case has been made that because Ireland's tax arrangements fulfilled OECD standards there was no substantiation that Ireland matched the conditions associated with tax haven status.
"The OECD's blacklisting process has been called into question due to the fact that it only listed one country Trinidad and Tobago as a tax haven."
The report - Blacklist or Whitewash: What a real EU blacklist of tax havens should look like - says financial flows are often completely out of proportion with the tax havens' real economic activity.
It states that in the British Virgin Islands foreign direct investment amounts to 90,000% of the country's GDP.
The corresponding figure for the Cayman Islands is 5,400% of the GDP, for Malta it is 650%, and for Luxembourg around 400% of GDP.
Oxfam said it is concerned that EU governments will come up with a weak, or even empty, blacklist and has urged the EU to put rules in place to reform the tax systems of EU countries such as Ireland, Luxembourg, the Netherlands, and Malta.
A spokesperson for the Department of Finance has said "Ireland has no harmful tax regimes."
He described Oxfam's report, which said Ireland would be blacklisted as a tax haven by the EU's own criteria as "totally inaccurate".
Oxfam's 'Blacklist or Whitewash' report stated that Ireland fails to meet the criterion on fair taxation.
However, the Department of Finance says this requirement is failed where a tax regime has been identified as harmful by the EU or OECD or if a country has a zero or almost zero tax rate.
"Ireland has no harmful tax regimes and this fact is endorsed by both the EU Code of Conduct group and the OECD Forum on Harmful Tax Practices," the spokesperson said.
