A European probe into the Irish taxes paid by technology giant Apple, as well as multi-nationals in Luxembourg and the Netherlands, is close to finishing.
The news came as Taoiseach Enda Kenny issues a robust defence of Ireland's corporate tax regime, which has been under international pressure in recent years as global agencies move to clamp down on tax reducing so called "profit shifting" by global companies.
"Ireland will play fair but we will play to win," Mr Kenny said at the Grant Thornton Worldwide Tax Conference in Dublin.
The 12.5pc corporate tax rate here is a corner-stone of economic policy, and will not change, he said.
Legislation to establish a so-called Knowledge Development Box, which is being designed to lower taxes for the most innovative companies, will be introduced in October this year, he said.
Meanwhile, EU Competition Commissioner Margrethe Vestager said yesterday that she "will be seeking to conclude shortly" the tax investigations into Apple in Ireland, Amazon and Fiat in Luxembourg and Starbucks in the Netherlands.
Brussels has asked all European Union members for information on how taxes are applied to companies, she said.
"I have also asked all EU member states to give us information on how they use tax rulings. On this basis, the Commission will assess the situation in every one of them to ensure that no individual companies get a selective advantage from paying unfair levels of tax," Commissioner Vestager said.
The Commission said last month it would miss its target to complete the tax probe that had been due to wind up by the middle of the year.
The formal investigation began in June 2014.
Brussels has accused Ireland of striking a tax arrangement with Apple that was based on keeping jobs here but which gave the company an advantage that amounted to state aid and went against international guidelines. The Government here has repeatedly said there is no case to answer.
All the companies involved in the EU probe have said that they acted within the law.
The Minister for Finance, Michael Noonan, said last year that he believed the Commission did not have a strong case, in relation to claims the tax treatment of Apple amounted to state aid.
Apple has warned investors that the cost could be "material" if it was ordered to pay past taxes to Ireland as a result of the EU investigation.