Cr.P.C Section 556

Case in which Judge or Magistrate is personally interested.

No Judge or Magistrate shall, except with the permission of the Court to which an appeal lies from his Court, try [* * *] any case to or in which he is a party, or personally interested, and no Judge or Magistrate shall hear an appeal from any judgment or order passed or made by himself.

Explanation.__ A Judge or Magistrate shall not be deemed a party, or personally interested, within the meaning of this section, to or in any case by reason only that he is a Municipal Commissioner or otherwise concerned therein in a public capacity, or by reason only that he has viewed the place in which an offence is alleged to have been committed, or any other place in which any other transaction material to the case is alleged to have occurred, and made an inquiry in connection with the case.
 

Illustration
A, as Collector, upon consideration of information furnished to him, directs the prosecution of B for a breach of the Excise Laws. A is disqualified from trying this case as a Magistrate.