Companies occasionally employ private investigators to uncover behaviors that could justify disciplinary action or even termination. The results of these probes are frequently challenged in court, and recent rulings from the Supreme Court have established a decisive jurisprudence on the limits of such surveillance. The core issue remains: how far can an employer go to verify claimed misconduct without infringing on a worker’s rights? And the courts now demand that any investigation be proportionate and respectful of dignity and privacy.
In one notable ruling, the court allowed the use of a detective even in cases where there was only a limited basis for concern about a worker’s behavior, stressing that evidence gathering must still comply with proportionality and privacy protections. The ruling underscores that hiring a detective can be appropriate when there are relevant indicators of misconduct, but it must be handled with care to avoid violating fundamental rights.
Pere Vidal, a partner at RocaJunent, highlights how the 2014 Private Security Law constrains data collection in such scenarios, especially when sensitive places like a worker’s home or other protected spaces are involved. He reminds readers that evidence obtained through improper surveillance can be deemed illegal for violating basic rights.
Thus, the recent decision, issued on September 12 by the Supreme Court’s Social Chamber, concerns a healthcare company operating in the Basque Country and Navarra. The company’s service included building cleaning, and the aim of employing detectives was to verify whether two window cleaners suspected of being distracted during work hours had spent part of the day in bars consuming alcohol.
The opinion, written by the judges Antonio Semper, Sebastián Moralo, and Ignacio García-Perrote, ruled on the validity of the dismissal of one of the workers, fully engaging with the questions of validity raised by earlier Bilbao and Basque High Court decisions. The rulings varied: while the lower courts deemed the evidence obtained by the private investigator illegal, the High Court of Justice of the Basque Country partially supported the company’s appeal, concluding the dismissal was unfair and ordering reinstatement or compensation for lost wages.
In the case at hand, the employee had thirty years of service under multiple contractual arrangements, finally providing services to the company on a schedule from six in the morning to one in the afternoon. The employee traveled between buildings in a company vehicle with a colleague.
From bar to pier
By mid-February 2021, detectives began monitoring the worker, and the inspector’s report cited several March days when alcohol consumption was noted. The resulting disciplinary proceedings led to a dismissal, while the colleague involved was suspended and paid wages for the period.
The company alleged that the worker had engaged in fraud, breached trust, shown disobedience, and demonstrated habitual intoxication and poor performance. The worker was accused of leaving work without justification and failing to adhere to the regular shift.
The Bilbao Social Court No. 6 found the dismissal invalid and ordered reinstatement, or, alternatively, a monetary award of 10,000 euros for damages resulting from the violation of fundamental rights stemming from surveillance. The Supreme Court later affirmed that the surveillance was illegal, noting that the company’s motive did not justify encroaching on privacy, and emphasized that the proportionality principle is essential when restricting fundamental rights. Without other corroborating evidence, the dismissal could not stand.
In the public prosecutor’s view, the company did present a well-documented account of facts known to the employer that led to hiring a detective, arguing that this did not infringe on the worker’s privacy. The prosecutor contended that the measure could be appropriate and proportionate when grounded in specific, job-related evidence.
We go down and play ball
In a contrasting scenario, the Catalonia High Court of Justice in 2017 deemed a dismissal permissible when the worker was on sick leave with tendinitis and observed engaging in activities such as playing ball, walking a dog, or other benign actions. The Supreme Court’s central inquiry in this line of cases focused on whether the company needed objective indicators of workforce mismatch to justify the detective’s testimony, and whether those indicators were present in the facts before the court.
Ultimately, the Supreme Court clarified that employers may require evidence of proper job performance and that the relevant measures must be proportionate, necessary, and appropriate, respecting the dignity of workers. It ruled that a company cannot justify surveillance based on vague suspicions alone; specific indicators must ground any investigative action. The court reminded that Article 20 of the Labor Code allows employers to monitor compliance, but such monitoring must respect privacy rights and not become a pretext for broad intrusions.
Respect for reserved spaces
In the Basque case, the court noted that surveillance did not occur inside the worker’s home or other highly private spaces. The company’s mission centered on work conducted outside the business site, and the matter was seen as a legitimate industry activity rather than a private space intrusion. The court indicated that the absence of well-founded doubts or a fixed numerical threshold for indicators does not automatically validate the evidence; instead, the proportionality test and the protection of privacy take precedence.
Nevertheless, even when the dismissal is not automatically invalid, the lack of proper accreditation for the alleged non-compliance can render the outcome unacceptable. This nuance underscores the delicate balance courts strike between protecting workers’ privacy and allowing legitimate management actions when justified by concrete, workplace-related concerns.
Residence limit
The analysis also reflects limits on surveillance conducted in non-designated areas. Recent Supreme Court decisions have reinforced that intrusions into a worker’s private space, such as a garden, or other areas that should be protected as private, are subject to strict scrutiny under the Private Security Law. In some instances, courts have upheld outside-the-building surveillance when it was clearly visible to passersby, but each case depends on the location and the scope of monitoring.
The lower courts have recognized that evidence must adhere to the proportionality, necessity, and suitability criteria while safeguarding fundamental rights. In a February 2021 Andalusian decision, a state agency supported hiring a detective to verify how time allocated for medical procedures was used, but the court later indicated that the investigation did not substantiate the claimed need when the worker’s actions proved to be non-work-related. The Supreme Court’s new stance, however, suggests that justifications must be carefully weighed and that blanket probes or investigations driven by mere business convenience are not acceptable. The emphasis remains on proportionality, necessity, and relevance to the worker’s duties.