Presumption of ownership and authenticity applies to assets and books found in a tax search or requisition, affecting evidentiary inference. Where books of account, other documents, money, bullion, jewellery or other valuable articles are found in a person's possession or control in the course of a search or survey, it may be presumed in proceedings under the Income-tax Act that the items belong to that person, that the contents of such books and documents are true, and that signatures and handwriting on them are those of the persons they purport to be; similar presumptions apply when such items are delivered to the requisitioning officer under requisition and custody procedures, treating the delivery as if the items had been found in a search.