Summons under Section 14 should be a last resort, not a tool to coerce payment of disputed dues. Summons under Section 14 are to be used only as a last resort where assessees are uncooperative or investigations require expeditious completion and must not be employed to coerce payment of disputed demands; normal recovery procedures should be followed. Collectors are personally responsible for enforcing these instructions and the Board will take serious view of unjustified issuance of summons to Managing Directors, Directors or other senior officers.