Section 59(1)(a) in The Punjab State Election Commission Act, 1994
(a)any ballot box used at a polling station or at a place fixed for the poll is unlawfully taken out of the custody of the Presiding Officer or the Returning Officer, or is accidentally or intentionally destroyed or lost, or is damaged or tampered with, to such an extent, that the result of the poll at that polling station, or place cannot be ascertained; or