Allowing the petition the court held that  A mere bald assertion by the AO that the assessee has not disclosed fully and truly all the material facts is not sufficient. The AO has to give details as to which fact or the material was not disclosed by the assessee, leading to its income escaping assessment. Otherwise, the reopening is not valid .  In order to sustain a notice seeking to reopen assessment beyond normal period of 4 years, it is necessary for revenue to establish, at least, prima facie that there was failure to disclose fully and truly all material facts necessary for assessment for that assessment year . (WP No 17 of 2020 dt 18 -02 2020  ) (AY. 2012 -13)