Unexplained investment treated as income when taxpayer offers no satisfactory source explanation and records are absent or deficient. Clause 103 deems an investment to be the assessee's income for a tax year where the investment is not recorded in the assessee's books or is found to exceed recorded amounts, and the assessee either offers no explanation as to the nature and source or offers an explanation that is not satisfactory to the Assessing Officer, thereby requiring inclusion of the value or excess amount in the assessee's total income.