Tribunal held that there was a survey and subsequently, assessment was completed on account of difference of labour charges amounting to Rs.1,59,53,033/- and this aspect was duly considered during the course of assessment proceedings. The AO nowhere said that there was a failure on the part of the assessee nor what was the new material came to his notice for reopening beyond the four years. Under these facts and circumstances of the case, if the AO want to reopen the assessment beyond the four years, he had to satisfy the conditions laid down by the proviso to S. 147. It is the duty of the AO to establish that there is a failure on the part of the assessee to disclose fully and truly all material facts to complete the assessment. The same aspect of difference of labour payments which had already been considered and it was not permissible to reopen the very same assessment after four years. Thus the notice issued by the AO under  S. 148 beyond four years was not valid and therefore reassessment was quashed.(AY.2010-11)