Evidence Act - section 106- "Section 106 of the Evidence Act does not abrogate the well-established rule of criminal law that except in very exceptional classes of cases the burden that lies on the prosecution to prove its case never shifts and section 106 is not intended to relieve the prosecution of that burden. On the contrary, it seeks to meet certain exceptional cases where it is impossible, or a proportionately difficult, for the prosecution to establish facts which are especially within the knowledge of the accused and which can be proved by him without difficulty or inconvenience.