Hiring a private investigator to verify potential irregularities during a period of temporary incapacity is lawful in Spain. However, an employer’s power of surveillance is not unlimited.

Any investigation must pursue a legitimate purpose, be based on specific indications and respect the employee’s fundamental rights. Where these requirements are not met, the investigator’s report may be deemed inadmissible and the employer may face employment-related and financial consequences.

The employer’s powers of supervision and control

The starting point is Article 20.3 of the Spanish Workers’ Statute, which allows employers to adopt such supervisory and control measures as they consider appropriate to verify compliance with employment obligations.

These powers must be exercised with due regard for the employee’s dignity and within the limits imposed by fundamental rights. They therefore do not justify indiscriminate investigations or surveillance based solely on general suspicion.

During a period of temporary incapacity, an employer may seek to determine whether an employee is carrying out activities that are incompatible with recovery or whether their conduct may amount to a breach of the duty of good faith.

However, the mere fact that an employee carries out an activity while on sick leave does not automatically constitute fraud. It is necessary to assess whether that activity may hinder recovery, unjustifiably prolong the period of incapacity or prove incompatible with the limitations that gave rise to the sick leave.

When may a private investigator be engaged?

Article 48 of Law 5/2014 of 4 April on Private Security allows private investigators to carry out investigations into conduct or events connected with the employment sphere, provided that they have been lawfully instructed to do so.

The engagement must be supported by a legitimate interest, and the investigation must comply with the principles of reasonableness, necessity, suitability and proportionality.

This means that the surveillance must be limited to the time, places and actions strictly necessary to verify the facts that prompted the investigation.

The same provision establishes a particularly important restriction: under no circumstances may an individual’s private life be investigated inside their home or in other private or restricted places.

The right to privacy as a limitation

An employer’s powers of control must be balanced against the right to privacy recognised in Article 18.1 of the Spanish Constitution.

For this reason, an investigation that may be lawful in a public place can become unlawful when it takes place inside the employee’s home or in an environment that, by its nature, must be regarded as private or restricted.

Private investigators may not use methods that infringe the rights to honour, personal or family privacy, one’s own image, confidentiality of communications or the protection of personal data.

The Supreme Court and photographs taken in a residential garden

The Employment Chamber of the Spanish Supreme Court considered the case of an employee who was on sick leave due to a cervical condition. The employer hired a private investigator, who photographed the employee carrying out physical tasks in the garden and vegetable plot of his home.

On the basis of those photographs, the employer dismissed the employee on disciplinary grounds, considering that he had carried out activities incompatible with his temporary incapacity.

The Supreme Court held that the evidence had been unlawfully obtained. It found that the garden formed part of an area in which the employee’s personal and family life was conducted and that it should therefore remain protected from third-party interference.

The judgment confirms that this protection is not limited to the physical interior of the home. It may also extend to outdoor areas connected to the residence where those areas are private or restricted.

Surveillance conducted at a private golf club

In another significant ruling, the High Court of Justice of the Basque Country upheld a judgment against a company that had hired a private investigator to follow an employee who was on sick leave.

Part of the surveillance took place inside a private golf club. The court found that this was a restricted space and that the surveillance had infringed the employee’s right to privacy.

The company was ordered to compensate the employee for the breach of his fundamental rights. This ruling shows that the concept of a restricted place is not necessarily confined to the home and may include other private spaces with controlled access.

Can a private investigator’s report be used as evidence in court?

Reports prepared by private investigators may be submitted as evidence in employment proceedings. Their admissibility, however, will depend on whether the investigation and the obtaining of images or information complied with the law.

Where evidence has been obtained through a breach of a fundamental right, it may be declared unlawful and excluded from the proceedings.

This may lead, among other consequences, to:

• The report being inadmissible in support of a disciplinary sanction or dismissal.
• The dismissal being declared unfair or, depending on the circumstances, null and void.
• The employer being ordered to pay compensation for the breach of fundamental rights.
• An investigation originally intended to protect the employer’s interests ultimately weakening its position in legal proceedings.

Precautions before hiring a private investigator

Before commissioning an investigation, the employer should verify that there are sufficient objective indications and clearly define the facts it seeks to establish.

It is also advisable to set clear limits on the scope of the engagement, avoiding excessively prolonged or open-ended surveillance and expressly excluding any investigation inside homes or other restricted places.

The measure must be proportionate to the seriousness of the conduct under investigation. Once the report has been received, its contents should also be reviewed from a legal perspective before any disciplinary decision is taken.

Hiring a private investigator may be a legitimate means of verifying potential employment-related misconduct, but it must be used with particular care. The existence of suspicions does not justify disregarding the fundamental rights of the person under investigation.

At Solium Legal, we advise companies and professionals on employment law, employer monitoring measures, disciplinary proceedings and the protection of fundamental rights.