Section 4426 - Habeas corpus; discharge by order of court(a) Every person committed or detained in a facility by reason of the provisions of this act or anyone acting on his behalf, may at any time, petition for a writ of Habeas Corpus and, except as hereinafter provided, said petition shall be filed in accordance with the provisions of the act of May 25, 1951 (P.L. 415). (b) Said petition may be based upon the following grounds:(1) The insufficiency or illegality of the proceedings leading to such person's commitment, or,(2) Although the commitment proceedings were proper, such person's continued detention or hospitalization is not warranted by reason of mental disability. Where the petition is based on this ground: (i) it shall be accompanied by the affidavit of a physician stating that he has examined the person and is of the opinion that such person is not mentally disabled, or that such mental disability does not require care or treatment in a facility, and (ii) the burden of proof shall rest upon the director responsible for such person's continued detention.(c) Jurisdiction and venue is hereby conferred upon the several courts of the Commonwealth to issue writs of Habeas Corpus filed under this act as follows: (1) A petition filed under section 426(b)(1) may be filed: (i) where committed by a court, only in the same court, or (ii) where committed under sections 404 or 405 of this act, only in the court of the county where the application for commitment was made.(2) A petition filed under section 426(b)(2) may be filed: (i) in the court which committed such person or the court of common pleas of the county where he is detained if a civil commitment was ordered, or (ii) where a criminal charge is pending, in the court having jurisdiction of the charge or which committed him or the court of the county where he is detained, or (iii) where committed by a court where a criminal act was in any way otherwise involved in the proceedings leading to commitment, only in the same court which committed such person.(3) If any petition under section 426(b)(2) is filed in a court other than the court of the county in which the person is detained, the petition may be transferred for disposition by the court in which it was filed to the appropriate court of the county in which the person is detained.1966, Special Sess. No. 3, Oct. 20, P.L. 96, art. IV, § 426, effective 1/1/1967.