Thu thập bằng chứng ngoại tình như thế nào là hợp pháp và được Toà chấp nhận? (Luật sư Lê Bình Phương phân tích)How to Collect Evidence of Infidelity Lawfully and Have It Accepted by the Court (Analysis by Lawyer Lê Bình Phương)

Reference translation for convenience. The Vietnamese version is the authoritative text.

Overview

When suspecting a spouse of infidelity, the first question many people ask is: “How do I collect evidence the court will accept?” But not every method of collection is lawful. The line between legally valid evidence and criminal conduct is sometimes very thin. Many people, acting in haste, have shifted from the role of plaintiff to that of defendant.

This article specifically analyses the types of evidence of infidelity that courts accept, lawful collection methods under current regulations, and the mistakes to avoid.

Relevant Legal Provisions

Obligation of fidelity and grounds for divorce:

Article 19 of the Law on Marriage and Family 2014 (52/2014/QH13) provides that spouses have a duty of fidelity to each other. A breach of this duty is a ground for the court to resolve a unilateral divorce under Article 56, paragraph 1, when the marriage has “fallen into a serious state such that their common life cannot continue.”

Resolution 01/2024/NQ-HĐTP, Article 4, paragraph 3(b) further clarifies: “A spouse having an extramarital affair” is one of the indicators establishing that a marriage is in a serious state — meaning the court must recognise this as a ground for divorce if proven. Infidelity also affects property division: Article 59, paragraph 2(d) of the Law on Marriage and Family allows the court to consider “the fault of each party in violating the rights and obligations of spouses.” The party at fault may receive a smaller share of the assets.

Conditions for evidence to be accepted by the court:

Article 93 of the Civil Procedure Code 2015 (92/2015/QH13) defines evidence as that which is “real” — objectively existing and verifiable. Article 94 lists 10 valid sources of evidence, including: readable documents, audio/video recordings, electronic data, and witness testimony. Article 95, paragraph 2 imposes a specific requirement on audio-visual materials: they must be accompanied by “a written document clearly stating the origin of that material.” A video or audio recording alone is insufficient; the specific source must be confirmed.

Limits on evidence collection:

Article 38 of the Civil Code 2015 (91/2015/QH13) protects the right to privacy in private life — no one may collect, store, or use information about another person’s private life without their consent, including between spouses. Article 159 of the Penal Code 2015 (consolidated 2025, 100/2015/QH13) provides for the offence of “Infringing the confidentiality or safety of correspondence, telephone, telegraph or other forms of private communication,” with penalties of up to 3 years’ imprisonment.

Analysis and Application

Types of evidence courts accept:

First, photographs and videos taken in public spaces — parks, cafés, streets, car parks. Public spaces are not protected by Article 38 of the Civil Code. These must be accompanied by a written document clearly stating the time and place, as required by Article 95, paragraph 2 of the Civil Procedure Code.

Second, text messages and emails that you yourself received. You are a party to the exchange and have the right to use that content as evidence. Screenshots are accepted if unaltered.

Third, audio recordings of a conversation in which you are a participant — for example, recording a face-to-face conversation with your spouse. Vietnamese law contains no prohibition on a participant in a conversation recording that same conversation themselves.

Fourth, witness testimony. Persons who directly witnessed the events and are willing to provide testimony under Article 94, paragraph 1(d) of the Civil Procedure Code. This is a highly reliable source of evidence because witnesses can be cross-examined at trial.

Fifth, invoices, bank statements, and hotel booking records. These prove unusual absences and unexplained expenditure. This type of evidence is often used in combination with others to build a cumulative case.

What is prohibited and may give rise to criminal liability:

Installing spyware on a spouse’s phone, intercepting calls you are not party to, breaking into their email or social media accounts, or placing listening devices in the home — all of these may constitute an offence under Article 159 of the Penal Code, with penalties ranging from non-custodial reform to 3 years’ imprisonment. In addition, unlawfully obtained evidence risks being excluded entirely by the court.

Real-World Situation

In a 2017 case before the People’s Court of Thủy Nguyên District (Hải Phòng), a wife proved her husband’s infidelity by going to the scene herself after being notified — witnessing it directly, without any surveillance device. The court admitted this evidence and, on the basis of Article 56, paragraph 1 of the Law on Marriage and Family, accepted the unilateral divorce petition, finding that the marriage had fallen into a serious state.

The notable point: the evidence accepted was not from eavesdropping or tracking software, but from lawful direct observation. This is a clear illustration of the principle that the method of collection matters no less than the content of the evidence.

In practice, many divorce cases involving infidelity are resolved by the court based on the parties’ own admissions at trial rather than on indirect evidence. Where the other party denies everything, evidence from public spaces combined with witness testimony typically carries considerably more weight than materials of unclear provenance.

Frequently Asked Questions

Can secretly taken photographs of a spouse’s infidelity in a public place be accepted by the court?
→ Yes, if taken in a public place and accompanied by a written document stating the time and place.

According to lawyer Lê Bình Phương, photographs taken in a park, café, or on the street satisfy the requirements of Articles 94 and 95, paragraph 2 of the Civil Procedure Code. By contrast, photographs taken in someone’s bedroom or other private space may violate Article 38 of the Civil Code and be rejected by the court.

Can I install tracking software on my spouse’s phone to obtain evidence of infidelity?
→ No — this conduct constitutes a criminal offence.

According to MBA., Esq. Lê Bình Phương, installing spyware on another person’s device — including a spouse’s — constitutes an infringement of the confidentiality of communications under Article 159 of the Penal Code, punishable by up to 3 years’ imprisonment. Evidence obtained in this way also risks being excluded entirely by the court.

Are a spouse’s text messages valid evidence in a divorce?
→ Yes, but only where you are the recipient or a direct participant in the exchange.

According to lawyer Lê Bình Phương, if you screenshot messages sent to you, that constitutes valid evidence under Article 94 of the Civil Procedure Code. However, if you break into their phone to view their messages to someone else, that is unlawful and the evidence may be rejected.

Important Notes

In civil proceedings — contested divorces — the court applies the “balance of probabilities” standard rather than the criminal standard of proof. This means: perfect evidence is not required, but there must be enough to persuade the court that the marriage has become serious within the meaning of Article 4, paragraph 3(b) of Resolution 01/2024.

One point frequently overlooked: proving infidelity is not always necessary for the court to grant a divorce. If the parties have in fact lived separately for over 12 months and there is sufficient basis to show that their common life cannot continue, the court may still grant the divorce without finding fault for infidelity.

Where common assets are substantial and you wish the court to consider fault in property division under Article 59, paragraph 2(d) of the Law on Marriage and Family, evidence of infidelity then carries real weight and must be prepared more systematically.

Related Articles

• Husband’s infidelity — can the wife receive a larger share of assets on divorce?
• Land use certificate in the husband’s name alone — can the wife claim a share on divorce?
• Divorce and child custody — what you need to know

Conclusion

Lawfully collecting evidence of infidelity turns on three principles: record only what takes place in a public space or within an exchange you participate in; retain full source information as required by Article 95, paragraph 2 of the Civil Procedure Code; and never install surveillance devices or software, as this may give rise to criminal liability under Article 159 of the Penal Code.

The line between valid evidence and criminal conduct is thin. Before collecting any material, consult a lawyer to protect your interests properly and avoid unnecessary legal risk.

See also: Who is Lawyer Lê Bình Phương?