Castellana Detectives works under the strictest legality and in compliance with the laws and regulations that regulate the sector.

Private Security Law

The private detective activity is regulated by the Law 5/2014 of 4 April, on Private Security..

Article 5. Private security activities

  1. Private Security activities are comprised by …
    • h) The private investigation in relation to persons, facts or crimes only prosecutable at the request of a party.
  2. The detective agencies can provide, with exclusive and exclusionary character, the services referred to in paragraph h) of the above point.

Services of the private detective agencies

Article 48. Private investigation services.

  1. 1. The private investigation services, assigned to private detectives, will consist of the realisation of enquiries that are necessary for the obtaining and provision, by legitimate third parties, of information and evidence on conducts or private facts related to the following aspects:
    • a) Those related to economic, labour, commercial and financial areas and, in general, personal, family or social life, excepting that which is carried out in the domiciles or reserved places.
    • b) The obtaining of information intending to guarantee the normal development of the activities that may take place in fairs, hotels, exhibits, shows, contests, conventions, large commercial areas, public places with large number of people, or similar areas.
    • c) The realisation of enquiries and the obtaining of information and evidence related to crimes only prosecutable at the request of a party by assignment of the legitimate subjects in the criminal process.

Law of Civil Procedure

Article 265. … The reports, worded by legally qualified private investigation professionals (private detectives) concerning relevant facts on which the said parties base their claims. If the said facts are not acknowledged as true, oral evidence shall be taken.


The Supreme Court defines the private detectives as privileged witnesses or with documents and adds in different rulings that they are “an instrument endowed with exclusivity for the effective control by the employer of the duties that may be demanded of the employee” (STS 6-11-90). This same ruling states that “the testimony given by the private detectives has, in favour of its veracity, not only the guarantee of demanded and in principle also presumable professionalism in a profession regulated by law, but also that which, in an undeniable way, provides the precise and continued dedication to the object of the ulterior testimony to issue and the complementary graphic or sound accreditations that may accompany it.”

"The Contentious-Administrative Court of the Supreme Court considers it legal for a public organisation to contract private detectives to investigate its civil servants during their working hours, since it does not violate their right to privacy.” (STS 12-05-98).