A European Commission investigation into Apple's tax affairs in Ireland, where it has a rate of less than 2 percent, has found that the company benefitted from illegal state aid, the Financial Times reported today reported citing sources close to the matter.
Ireland is favoured as a European base by several major companies including Amazon, Facebook, PayPal and Twitter.
Apple's European headquarters is in the southwest Irish city of Cork, where it employs 4,000 people.
The country has a competitive corporate tax rate of 12.5 percent, which has been criticised by some other member states of the EU as unfair, but which Dublin has repeatedly defended.
But a 2013 investigation by the US Senate found that the maker of iPhones and iPads paid a lower rate by channelling overseas sales through subsidiaries in a deal negotiated with the Irish government.
Apple did not immediately respond to comment, but both Ireland and Apple have denied the company was given a special deal.