A single Judge of Madhya Pradesh High Court at Gwalior Bench held that one fundamental right under Constitution must yield to another and, the right to fair trial must yield to right to privacy.

From Paras 11 and 12,

11. In order to achieve its object to simplify the rules of evidence and procedure, Section 14 of the Family Courts Act provides for an exception to the general rule of evidence regarding admissibility of any report, statements, documents, information or matter, which it considers necessary to assist it and to deal with it effectively. Apparently, such a provision is made keeping in view the nature of cases which are dealt with by the Family Courts. Needless to mention here that Section 14 of Family Courts Act is a special legislation and by virtue of this provision, the strict principles of admissibility of evidence as provided under the Evidence Act have been relaxed.
12. A cumulative reading of Section 14 & 20 of the Family Courts Act, takes within its ambit the restricted applications of the provisions of the Evidence Act qua the documentary evidence which includes electronic evidence, whether or not the same is otherwise admissible. The only guiding factor is that the Family Court should be of the opinion that such evidence would assist the Court to deal with the matrimonial dispute effectively. It is the absolute power and authority of the Family Court either to accept or discard particular evidence in finally adjudicating the matrimonial dispute. However, to say that a party would be precluded from placing such documents on record and/or such documents can be refused to be exhibited unless they are proved as per Evidence Act, runs contrary to the object of Section 14 of the Family Courts Act.

From Paras 18 and 19, (No fundamental right under our Constitution is absolute)

18. By reading the dictum of Apex Court in the case of Sharda & Puttaswami (supra), it is evident that right to privacy is recognized as a fundamental right under Article 21 of Constitution, but the same is not an absolute right. In case of necessity, a law can be framed permitting invasion to life and personal liberty. Section 14 of Family Courts Act and Section 122 of Indian Evidence Act are some such statutory provisions which permits invasion to right to privacy. It is worth mentioning here that vires of either of the aforesaid provisions are not under challenge and, therefore, the same have to be deemed as valid, fair and reasonable.
19. Since no fundamental right under our Constitution is absolute, in the event of conflict between two fundamental rights, as in this case, a contest between the right to privacy and the right to fair trial, both of which arise under Article 21 of our Constitution, the right to privacy may have to yield to the right to fair trial. Reference in this regard can be made to the observations of a 5-Judge Constitution Bench decision of Apex Court in Sahara India Real Estate Corporation Limited Vs. Securities and Exchange Board of India reported in (2012)10 SCC 603

From Paras 20 and 21,

20. Reading the law laid down by Apex Court in the case of Sharda, Puttaswamy & Sahara India (supra), it comes out loud and clear that even though right to privacy has been recognized as a fundamental right, the same is not absolute and is subject to exceptions and limitations. While a litigating party certainly has a right to privacy, that right must yield to the right of an opposing party to bring evidence it considers relevant to court, to prove its case. It is a settled concept of fair trial that a litigating party gets a fair chance to bring relevant evidence before court. It is important to appreciate that while the right to privacy is essentially a personal right, the right to fair trial has wider ramifications and impacts public justice, which is a larger cause. The cause of public justice would suffer if the opportunity of fair trial is denied by shutting-out evidence that a litigating party may wish to lead, at the very threshold. Saying otherwise, would negate the specific statutory provision contained in Section 14 of Family Courts Act, which says that evidence would be admissible, whether or not the same is otherwise admissible under Evidence Act.
21. If it were to be held that evidence sought to be adduced before a Family Court should be excluded based on an objection of breach of privacy right then the provisions of Section 14 would be rendered nugatory and dead-letter. It is to be borne in mind that Family Courts have been established to deal with matters that are essentially sensitive, personal disputes relating to dissolution of marriage, restitution of conjugal rights, legitimacy of children, guardianship, custody, and access to minors; which matters, by the very nature of the relationship from which they arise, involve issues that are private, personal and involve intimacies. It is easily foreseeable therefore, that in most cases that come before the Family Court, the evidence sought to be marshaled would relate to the private affairs of the litigating parties. If Section 14 is held not to apply in its full expanse to evidence that impinges on a person’s right to privacy, then not only of Section 14 but the very object of constitution of Family Courts shall be frustrated. Therefore, the test of admissibility would only be the relevance. Accordingly, fundamental considerations of fair trial and public justice would warrant that evidence be received if it is relevant, regardless of how it is collected. The purpose of legislating Section 14 would be frustrated if it is to give way to right of privacy.

From Para 35,

35. In view of the discussion made above, this court is of the opinion that the Legislature, being fully aware of the principals of admissibility of evidence, has enacted Section 14 in order to expand that principle in so far as disputes relating to marriage and family affairs are concerned. The Family Court is thereby freed of restrictions of the strict law of evidence. The only test under Section 14 for a Family Court to receive the evidence, whether collected legitimately or otherwise, is based upon its subjective satisfaction that the evidence would assist it to deal effectually with the dispute.

From Para 38,

38. In view of the discussion made above, it is held that:
(a) the evidence is admissible so long as it is relevant, irrespective of the fact how it is collected. The possible misuse of this rule of evidence, particularly in the context of the right to privacy, can be addressed by prudent exercise of judicial discretion by the Family Court, not at the time of receiving evidence but at the time of using evidence at the stage of adjudication;
(b) merely admitting evidence on record is not proof of a fact-in-issue or a relevant fact. Admitting evidence is not even reliance by the court on such evidence. Admitting evidence is mere inclusion of evidence in record, to be assessed on a comprehensive set of factors, parameters and aspects, in the
discretion of the court;
(c) the test of ‘relevance’ ensures that the right of a party to bring evidence to court, and thereby to a fair trial, is not defeated. What weight is to be given to evidence so brought-in, and whether or not the court ultimately relies upon such evidence for proof of a fact-in-issue or a relevant fact, is always in the discretion of the court.
(d) merely because a court allows evidence to be admitted, does not mean that the person who has illegally collected such evidence is absolved of liability that may arise, whether in civil or criminal law or both;
(e) such evidence must be received and treated with caution and circumspection and to rule-out the possibility of any kind of tampering, the standard of proof applied by a court for the authenticity and accuracy of a such evidence should be more stringent as compared to other evidence;

Index of Divorce Judgments is here.