More than €21.4m was owed by tax defaulters between January and March, according to Revenue
Interest of more than €2.55m was added to that, along with a Revenue penalty of nearly €4.58m.
The full amount remained unpaid at the end of March, according to Revenue.
The case is one of 30 tax settlements published by Revenue, covering the three months between January and March 2021. However it represents more than half the value of the settlements agreed.
The next largest settlement in the quarter related to Ohshima Ireland Limited, a precision metal component manufacturer based in Santry in north Dublin.
An audit by Revenue found it had under-declared corporation tax, PAYE, PRSI, USC and VAT to the tune of more than €2.51m.
Interest of €737,100 was applied, along with a €749,000 fine, bringing the total amount owed to more than €4m.
The amount was paid in full by the end of March.
Meanwhile, Ray Sean McDermott, a medical consultant based in Sandyford in south Dublin, was found to owe Revenue more than €1m following an audit.
That was due to more than €593,000 in under-declared income tax, with interest of more than €301,000 and a penalty of more than €171,000 applied.
Almost €524,000 of that had yet to be paid by the end of March.
As part of the defaulters list, Revenue also published details of 44 tax cases that were subject to a court fine or penalty.
They were worth a combined €106,000 in the three month period.