Section 755 ILCS 5/5-3 - Power to ascertain and declare heirship - evidence(a) The court may ascertain and declare the heirship of any decedent to be entered of record in the court at any time during the administration of the estate without further notice or, if there is no grant of administration, upon such notice and in such manner as the court directs.(b) The ascertainment of heirship may be made from (1) an affidavit of any person stating the facts from which the heirship of the decedent can be ascertained, which affidavit shall be signed and sworn to or affirmed before any notary public or judge of any court of record in the United States or any of its possessions or territories and certified by the clerk thereof, or before any United States consul, vice-consul, consular agent, secretary of legation or commissioned officer in active service of the United States, within or without the United States, or (2) from evidence either in narrative form or by questions and answers which are reduced to writing and certified by the court declaring the heirship. The seal of office of any notary public, United States consul, vice-consul, consular agent or secretary of legation and the designation of the name, rank and branch of service of any commissioned officer in active service of the armed forces of the United States shall be sufficient evidence of his identity and official character. The affidavit or transcript of evidence shall be filed by the clerk of the court declaring the heirship and remain as a part of the files in the cause.(c) An order of the court declaring heirship is prima facie evidence of the heirship, but any other legal method of proving heirship may be resorted to by any party interested therein in any place or court where the question may arise.(d) For purposes of this section the court may presume, in the absence of any evidence to the contrary, that the decedent and any person through whom heirship is traced was not the mother or father of any child born out of wedlock and, if the decedent or the person was a male, that no child born out of wedlock was filiated to or acknowledged or legitimated by the decedent or the person.