Capital gains liability applies where assets declared under a disclosure scheme are taxed at fair market value on declaration. Where an undisclosed asset is declared under the Scheme and tax, surcharge and penalty are paid on its fair market value as of the Scheme valuation date, the declarant remains liable for capital gains on any future sale; the cost of acquisition for computing capital gains is the fair market value used for the Scheme and the holding period commences from that valuation date.