(1) In this section, "particular gains" means chargeable gains accruing from the disposal of assets situated outside the State, the amount of which is or is included in the amount (in this section referred to as "the relevant amount") on which in accordance with the Capital Gains Tax Acts the tax is computed.
(2) Subject to subsections (3) to (5), this section shall apply where capital gains tax has been charged by an assessment for the year in which the particular gains accrued and the tax has not been paid.
(3) In any case in which, on or after the date on which the capital gains tax has become payable, such proof is given to the Revenue Commissioners as satisfies them that particular gains cannot, by reason of legislation in the country in which they have accrued or of executive action of the government of that country, be remitted to the State, the Revenue Commissioners may for the purposes of collection treat the assessment as if the relevant amount did not include the particular
…