Judgment S. Narayan, J.: 1. The parties have already exchanged affidavits in terms of order dated 30.7.1996. Heard learned counsel appearing on the either side. 2. This appeal is directed against an Order dated 17.5.1996 of the 11th Court of Additional District Judge, Alipore, whereby the custody of a minor son, Joydeep Gupta, was directed to be made over by the O.P.-father (i.e. the appellant) in favour of the petitioner-mother (i.e. the respondent). The appellant-father, being aggrieved of the order has come up with the present appeal along with a prayer for stay of the impugned order; 3. The minor son, Joydeep Gupta, was admittedly born on 13.9.85 out of the wedlock of the appellant and the respondent, who lived separately for the present. The son was presently in custody of the father and, accordingly, the respondent-mother filed petition praying for custody of her minor son u/s. 6 of the Hindu Minority and Guardianship Act read with s. 26 of the Guardian and Wards Act, 1890. It was contended therein that the appellant-father had since married for the second time a woman named, Chandrima Banerjee, and that after the marriage he shifted from his house situate at 36/5, Pasupati Bhattacharyay Road, Behala, Calcutta to another house situate at 36/2, Baranagar Lane, Alam Bazar, P.S. Baranagar, Calcutta with the minor son, Joydeep. The respondent-wife was still living in her matrimonial home situate at Behala. The appellant had got one more son and a daughter out of the wedlock with Chandrima Banerjee. The appellant had to remain engaged in business in his house situate at Behala from 8 a.m. to 9 p.m. and, accordingly, Joydeep was left un cared in custody of her step-mother, Chandrima. Hence, there was need for transfer of custody of Joydeep from his father to his mother in the wider interest of his welfare. 4. The appellant-father has, however, denied his marriage with Chandrima Banerjee as also of having any child from her. It was asserted that Joydeep was under proper care and protection in his custody and was having his adequate educational facility with him. According to the appellant, the respondent-mother left her materimonial home of her own accord without caring for the minor son and, accordingly, the welfare of the child was not secured with her. 5. It was asserted that Joydeep was under proper care and protection in his custody and was having his adequate educational facility with him. According to the appellant, the respondent-mother left her materimonial home of her own accord without caring for the minor son and, accordingly, the welfare of the child was not secured with her. 5. At the very outset, it is noticed on the face of the impugned order as a striking feature that the finding of the court below has been arrived at without any legal evidence, either oral or documentary, in spite of the fact that the parties contested the claim of each other on some basic facts. The solitary ground as raised on behalf of the respondent-mother praying for the custody was that the appellant had since married, Chandrima Banerjee, and they had off springs of the said marriage and, therefore, while the appellant was away from his house to look after his business, the minor son, Joydeep, was neglected by the said Chandrima Banerjee i.e. the second wife of the appellant. In support of this contention, the court below appears to have placed reliance on a duplicate copy of the certificate of marriage produced by the respondent-mother. It was accepted by the court as gospel truth on the basis of the said certificate that the appellant was married to Chandrima Benerjee by way of registration of the marriage on 10.5.1993 having effect of the marriage from an earlier date i.e. on 34.1.1983. It was also taken note of a peculiar fact mentioned in the duplicate copy of the certificate that the minor son, Joydeep, was an off springs out of the wedlock between the appellant and Chandrima Banerjee with reference to his date of birth as on 13.9.1985. The allegation of remarriage had, however, been emphatically denied on behalf of the appellant before the court below. Hence, because of the controversy raised as such, it was in the fitness of things that both the parties should have been given an opportunity to adduce oral as well as documentary evidence. The allegation of remarriage had, however, been emphatically denied on behalf of the appellant before the court below. Hence, because of the controversy raised as such, it was in the fitness of things that both the parties should have been given an opportunity to adduce oral as well as documentary evidence. It may be added here that as against the aforesaid marriage certificate, the appellant filed before us through an affidavit-in-reply a copy of a decree passed in T.S. No. 109 of 1993 of the court of Munsiff, Kalyani, District Nadia whereby the aforesaid marriage certificate was declared to be illegal, void and inoperative, which one of the two versions about the re-marriage of the appellant was acceptable in the eye of law would depend solely upon the evident"' adduced on the either side. That being as such, it would be difficult to sustain the impugned order which has been recorded without reference to admissible evidence. 6. Ld. counsel for the appellant has very emphatically urged while drawing our attention to the legal proposition as provided u/s. 13 of the Guardians and Wards Act as also Rule 296 of the West Bengal Civil Rules and Order that in view of the controversy raised on the relevant facts of the case it was expected of the court below to have called upon the parties to adduce evidence in support of their respective contention rather than to have accepted the contents of a duplicate copy of the marriage certificate without asking for the original thereof and proving the same in due course of the proceeding. 7. Before suggesting a legal recourse in the matter it may also be pointed out that the court below appears to have formulated a point for consideration in the impugned order as if he was required to answer that who would be a natural guardian of the minor Joydeep. Most certainly the parties have not joined issue on that point because the father was admittedly the natural guardian of Joydeep. The controversy raised before the court below was basically with regard to whether the respondent-mother \vas entitled to the custody of minor son being taken out from that of the natural guardian i.e. the appellant-father. The paramount consideration to determine the custody of a minor son was the ultimate welfare of the child for his proper care and upkeep as well as his educational facility. 8. The paramount consideration to determine the custody of a minor son was the ultimate welfare of the child for his proper care and upkeep as well as his educational facility. 8. The essence of a fair trial is adjudication of facts in controversy only after affording adequate opportunity to both the sides to adduce evidence in support of their respective contention. An analysis of the situation in which the impugned order seems to have been passed, however, depicts that an inadmissible duplicate copy of a Marriage Certificate was accepted by the court below to form an opinion in favour of the petitioner-mother. Though the O.P.-father challenged the facts, contained in the certificate, he failed to bring on the record the judicial pronouncement as to the validity of the Marriage Certificate. In a situation like this, it has to be borne in mind that the occasion to adduce evidence of rebuttal arises only when an admissible piece of evidence is adduced on the record through a legal process. As against an inadmissible document on the record, one may not be required to rebute it by any counter evidence. Accordingly, in the instant case, the O.P.-father might have abstained from producing the court's verdict declaring the Marriage Certificate as void and inoperative for want of production of the original Marriage Certificate and, in the alternative, for want of formal proof of the secondary evidence in accordance with law. 9. In the given facts and circumstances of the case we are persuaded also to observe that when both the parties were possessed of documentary evidence in support of their respective contentions, it was incumbent upon the court also to have insisted upon adducing such evidence on the record in accordance with law before accepting contents of either of the document. A court of law can of course draw an adverse inference on non-production of a paper but not before affording an adequate opportunity for the same. It has to be seen that an ignorant litigant does not suffer injustice for want of proper legal advise to adduce evidence in accordance with law. 10. For the reasons, aforesaid we are of the considered opinion that the impugned order can not be sustained in the eye of law and that the controversy between the parties is required to be determined by the court below in the light of the observations made above. 10. For the reasons, aforesaid we are of the considered opinion that the impugned order can not be sustained in the eye of law and that the controversy between the parties is required to be determined by the court below in the light of the observations made above. Of course, we abstain ourselves expressing any opinion as to the merits of the case and it is open for the court below to arrive at a fresh conclusion after affording opportunity to adduce evidence on the either side. 11. The appeal is thus admitted; and the same being treated for hearing on the days list is allowed at the stage of the admission. The impugned order is set aside and the case is remanded to the court below for fresh hearing and disposal in accordance with law. 12. There shall be no order as to costs. S. R. Misra. J.: I agree. Appeal allowed. Impugned order set aside.