Section 3(6) in The Delhi Municipal Corporation (Sealing Of Un-Authorised Construction) Rules, 1986
(6)Where any premises or unauthorised construction which has been ordered to be sealed under this rule is found to be locked or inaccessible, the person, municipal officer or other municipal employee authorised to seal the premises or the unauthorised construction, may either break open the lock or open or cause to be opened any door, gate or any other barrier and enter the unauthorised construction or the premises where the unauthorised construction has been made or is being made so as to ensure that the unauthorised construction or the premises is secured from within and then lock and seal the premises or the unauthorised construction:Provided that where any premises or the unauthorised construction is forced open, an inventory of the articles or material found in the premises or on the site of the unauthorised construction shall be prepared in the presence of two witnesses and a copy thereof shall be delivered to the owner or occupier present at the site.
