As per Section 67(1), Inspection can be carried out by any officer of Central tax only upon a written authorization in Form GST INS-01 given by a proper officer not below the rank of Joint Commissioner. Such proper officer can give such authorization only if he has reasons to believe that the person concerned has–
(a) suppressed any transaction of supply;
(b) suppressed stock of goods in hand;
(c) claimed excess input tax credit;
(d) contravened any provisions of this Act or rules made there under to evade tax;
(e) a transporter or an owner or operator of a warehouse or godown or any place, has kept goods which have escaped payment of tax or has kept his
accounts or goods in a manner that is likely to cause evasion of tax.
(ICAI FAQ PUBLICATIONS : – 06-09-2017 -INSPECTION, SEARCH, SEIZURE AND ARREST : FAQ NO.4)