see s189 TCA 1997 payments in respect of personal injuries.
in short, "relevant income" means income arising from investments of compensation (includes income under Case IV which is Deposit Interest).
if the relevant income exceeds 50% of the total income arising to an individual in a tax year, the relevant income shall be exempt from income tax, but the person will still need to submit a tax return.
so looks like the deposit interest is taxable. compensation is not taxable under s613(1)(c) TCA 1997