Concurrent jurisdiction: Inspecting Assistant Commissioner may exercise and direct Wealth tax Officer functions, subject to hearing before prejudicial instructions. Section 8AA authorized the Commissioner to direct that powers or functions of Wealth tax Officers be exercised concurrently by an Inspecting Assistant Commissioner for specified areas or classes, required Wealth tax Officers to act as directed by the Inspecting Assistant Commissioner, and mandated observance of that officer's instructions in particular proceedings subject to an opportunity for the assessee to be heard before any instruction prejudicial to the assessee; an explanation excluded investigative directions from being treated as prejudicial, and statutory references to Wealth tax Officers were to be read as references to the Inspecting Assistant Commissioner where powers were exercised by the latter.