What a matrimonial investigation in Spain covers
A matrimonial investigation Spain is a structured, lawful enquiry into facts that matter to a marriage, separation or divorce. Typical objectives include confirming whether a spouse is in a new relationship, documenting a partner's daily lifestyle and routine, locating a spouse who has moved or left, verifying whether an ex-partner is now cohabiting with someone else, and assessing parenting conduct. A family investigation Spain can also extend to wider household circumstances where these bear directly on a legal matter.
The service is widely used by expatriates and international families with interests in Spain, by spouses involved in cross-border divorces, and by law firms that need facts gathered on the ground in Spain by a professional who can later testify. The aim is never gossip or pressure: it is to establish, objectively and lawfully, what is actually happening, so that decisions and legal arguments rest on verified facts rather than suspicion.
Is a matrimonial investigation lawful? Legitimate interest and limits
In Spain, only a licensed private detective may lawfully investigate another person, under the Private Security Law (Ley 5/2014). The legal basis for a matrimonial enquiry is legitimate interest: under GDPR and Spanish data protection rules, a spouse generally holds a legitimate interest in matters that directly affect the marriage, which allows a professional to gather and document relevant information proportionately.
That interest is not unlimited. Investigations must respect fundamental rights: detectives cannot intercept private communications, place hidden cameras in private spaces, or enter a home unlawfully. Observation is conducted in public or publicly accessible spaces and recorded objectively. This is precisely why do-it-yourself surveillance is risky, frequently unlawful, and often rejected by a court, whereas a licensed professional keeps the work within the law and the findings usable.
Infidelity investigations and what they mean in a Spanish divorce
A lawful infidelity investigation relies on discreet observation in public settings to confirm and document whether a spouse is in a relationship, where they spend their time, and with whom. The work is carried out without harassment and without breaching anyone's privacy, producing a clear, dated record rather than assumptions.
It is important to be realistic about the legal effect. Since the 2005 family-law reform, Spanish divorce is no-fault, so adultery in itself does not change the financial settlement or automatically penalise a spouse. Where infidelity findings genuinely matter is in connected questions: child custody and parenting conduct, spousal and child support, the division of assets, and proof that an ex-spouse is cohabiting with a new partner, which may extinguish a compensatory pension (pensión compensatoria).
Child custody investigations and the welfare of the child
In custody disputes, Spanish courts are guided by the welfare of the child. A child custody investigation gathers lawful, objective evidence on factors a judge weighs: who genuinely cares for the children day to day, the suitability of the home environment, exposure to risk or unsuitable situations, and compliance with court-ordered arrangements such as contact schedules or relocation.
These enquiries are handled with particular sensitivity and always within legal limits. The goal is to give the court and your lawyer a factual, verifiable picture of the children's real circumstances, documented in a way that can be examined and challenged, rather than untested allegations from either parent.
Spousal hidden income and undisclosed assets
Financial transparency is often the most contested part of a separation. A spousal hidden income enquiry lawfully examines signs of undeclared earnings, off-the-books business activity, or a lifestyle plainly inconsistent with declared means, as well as assets that may have been placed in the names of relatives or third parties.
Documented properly, these findings support a fair calculation of spousal and child support and an accurate division of assets. Where the financial picture is complex or spans companies and property, this work connects naturally with asset tracing, so that what is found can be presented credibly to the court.
Evidence in family proceedings: the detective's report
What makes professional findings valuable is admissibility. Under article 265.1.5 of the Spanish Civil Procedure Act (LEC), a licensed detective's report is admissible documentary evidence in civil and family proceedings, and the detective can ratify the report and be examined in court. Combined with the investigator's TIP (professional ID) and entry in the National Private Security Registry (RNSP), this gives the evidence weight that informal recordings or screenshots rarely carry.
In short, a licensed detective bridges the gap between what you suspect and what a judge can rely on. The report sets out facts, dates and methods clearly, withstands cross-examination, and supports your lawyer's strategy. To use evidence in family proceedings effectively, contact La Sociedad Clave and we will connect you with the right licensed professional.
Frequently asked questions
Is it legal to hire a private detective to investigate a spouse in Spain?
Yes. Under Spain's Private Security Law (Ley 5/2014), a spouse generally holds a legitimate interest in matters affecting the marriage, so a licensed detective may investigate lawfully. The work must respect fundamental rights, avoiding intercepted communications or hidden recording in private spaces. Only licensed professionals should carry it out.
Does proof of infidelity affect a divorce in Spain?
Not directly. Since the 2005 reform, Spanish divorce is no-fault, so adultery alone does not change the financial settlement. Findings still matter where conduct affects child custody, spousal or child support, asset division, or proof of cohabitation that may extinguish a compensatory pension.
Can a detective's report be used in a child custody case?
Yes. Under article 265.1.5 of the Spanish Civil Procedure Act, a licensed detective's report is admissible documentary evidence, and the detective can ratify it in court. In custody matters, lawful findings on parenting conduct, the home environment and care arrangements help the judge assess the child's welfare.
Can a private detective find a spouse's hidden income or assets?
Licensed detectives can lawfully investigate signs of undeclared income, off-the-books business activity, or a lifestyle inconsistent with declared means, as well as assets registered through third parties. These findings, documented in an admissible report, support fair spousal and child support and a correct division of assets.
Can investigators record private conversations or enter a home?
No. Spanish law protects fundamental rights, so detectives cannot intercept private communications, place hidden cameras in private spaces, or enter a home unlawfully. Observation takes place in public spaces. This is why do-it-yourself surveillance is risky and often inadmissible, while professional, lawful work stands up in court.
How do I start a matrimonial investigation in Spain?
Contact La Sociedad Clave with a brief outline of your situation and what you need to establish. We will connect you with a licensed private detective who will assess feasibility, define a lawful scope, and gather findings in an admissible report that you and your lawyer can use.
Contact La Sociedad Clave and we will connect you with a licensed private detective to handle your matrimonial or family matter lawfully and discreetly in Spain.