Hundi transactions treated as income, triggering special tax and penalty provisions for undisclosed borrowings and repayments. Amounts borrowed on or repaid by hundi otherwise than through an account-payee bank cheque are deemed income of the borrower or repayer for the year in which the transaction occurs, with repayment including interest. When total income includes such deemed unexplained amounts, a special tax treatment applies: those amounts are taxed under a distinct regime with no deduction or set-off allowed, an additional surcharge increases the computed tax, and designated officers may impose an extra penalty on the tax payable unless the income was declared and taxed under the special provisions in the return.