Based on the provided legal document, here are the key points regarding the mandatory examination of an approver under Section 306(4)(a) Cr.P.C. and the High Court's suo motu powers:

Mandatory Examination of an Approver * An accused who has been tendered a pardon under Section 306(4)(a) of the Code of Criminal Procedure must be mandatorily examined as a witness before the case is committed to the Sessions Court [judgement_subject]. * This examination is a statutory obligation imposed on the prosecution to ensure the approver has not resiled from their former position and has fulfilled the conditions of the pardon [15000536530011]. * The examination by the Magistrate is not a substitute for the formal examination required under the provision; it is compulsory [15000536530012]. * If a Magistrate fails to examine the approver prior to committing the case to the Sessions Court, it is illegal to omit that person from the array of accused [15000536530013]. * The proper procedure requires that if an accused accepts a pardon, they must be examined by the Magistrate taking cognizance of the offence before the case can be committed for trial [15000536530013].

Effect of Failure to Examine * Failure to examine the approver before committal vitiates the order of committal, rendering the process without authority and irregular [15000536530013]. * When such a failure occurs, the orders of committal are illegal and liable to be set aside [15000536530017]. * The case records must be transmitted to the committal court for fresh consideration of committal after complying with the provisions of Section 306(4)(a) Cr.P.C. [15000536530018].

High Court's Suo Motu Powers * There are no limitations on the exercise of the suo motu powers of revision by the High Court [judgement_subject]. * Even if an order of committal is considered an interlocutory order, the High Court can interfere with it under its suo motu powers to correct illegalities [15000536530014]. * Ex-facie illegal orders can be interfered with when they come to the notice of the High Court, regardless of procedural limitations [15000536530014]. * The High Court exercises plenary jurisdiction under suo motu powers coupled with powers under Section 482 Cr.P.C. to rectify illegalities in the broad interests of justice [15000536530014].

Statutory Provisions * Section 306 of the Cr.P.C. empowers a Magistrate to tender a pardon to an accomplice to obtain evidence, on the condition of full and true disclosure (!) . * Under Section 306(4)(a), every person accepting a tender of pardon shall be examined as a witness in the Court of the Magistrate taking cognizance of the offence and in the subsequent trial (!) . * The Magistrate must record reasons for tendering a pardon and furnish a copy to the accused upon application (!) .