Old lawyer

I note the Admin 25 Response to Chalkyboy from a month ago. i had understood that repayment interest is payable on early payment of CGT but that it is not taxable, so interest at the current rate of 3.5% equates to a little over 5.8% for a 40% taxpayer. Can Admin 25 clarify, please - not my figures but whether interest is payable on early payment of CGT by an individual taxpayer? Thanks