S. 69C : Unexplained expenditure – Bogus purchases – Information from sales tax Department – Sales not doubted – Books of account not rejected – Order of Tribunal affirming the estimate of profit at 12. 5% of alleged bogus purchases are affirmed – Court also observed that , it is the solemn obligation and duty of the Income Tax Authorities and more particularly of the A.O. to undertake all necessary enquiry including to procure all the information on such transactions from the other departments / authorities so as to ascertain the correct facts and bring such transactions to tax. [ 133(6), 145 (3)]