A pharmaceutical company facing a €1.6 billion tax demand from Revenue, says it will fight the decision through all available avenues.
The assessment made against Elan Pharma relates to the amount of tax paid on the sale of its stake in the groundbreaking drug Tysabri.
After the Apple tax case, it's the biggest ever corporate tax bill lodged by the Revenue Commissioners.
Perrigo which owns Elan issued a statement this evening, saying it strongly disagrees with decision.
It claims it contradicts Revenue's own guidance on such cases.
"Perrigo strongly disagrees with this assessment and believes that the Notice of Amended Assessment is without merit," they said.
"The Company asserts that Irish Revenue’s position is incorrect as a matter of law, based upon applicable case law, as well as both Irish Revenue published guidance and their related published precedents. In addition, no payment of any amount related to this assessment is required to be made, if at all, until all applicable proceedings have been completed, which could take a number of years. The Company will file an appeal and intends to contest the assessment vigorously through all available administrative and judicial avenues."
Perrigo's planning an appeal, which could lead to a lengthy legal battle.