The Investigador is a buoy tender, and she often does work for Puertos del Estado, the Spanish government agency responsible for operating Spain's ports and for maintaining aids to navigation. When she recovered the RU-27, she was working for Puertos del Estado.
Puertos del Estado is part of the Ministry of Development, and is roughly analogous to the American National Oceanic and Atmospheric Administration (NOAA). That is, in addition to running the ports and taking care of Spain's maritime infrastructure, the agency is heavily involved in oceanographic research, and therefore very interested in new ways to do that research. Scientists from Puertos del Estado have been heavily involved in this project, and arranging for the Investigador to retrieve RU-27 was part of that involvement.