21. The rate of customs duty or excise duty and the valuation, if any, applicable to any goods shall be —
(a)
in the case of goods lawfully imported or manufactured in Singapore —
(i)
if the goods are in a Government warehouse, licensed factory warehouse or licensed warehouse, the rate and valuation in force at the time when those goods are removed from the Government warehouse, licensed factory warehouse or licensed warehouse, as the case may be;
(ii)
if the goods are imported by post, the rate and valuation in force at the time when customs duty or excise duty is assessed by the proper officer of customs; and
(iii)
in any other case, the rate and valuation in force at the time when the goods are released by the proper officer of customs; and
(b)
in the case of uncustomed goods, the rate and valuation in force at the time when the goods became uncustomed goods, if known, or the rate and valuation in force at the time of seizure, whichever is the higher.