The Guardia Civil's Seprona division report that two people are under formal investigation in connection with the deaths of 27 dogs in November last year.
On the first of November, the dogs were found dead in an animal-transportation van when a ferry from Barcelona docked in Palma. Nine other dogs showed severe signs of asphyxiation and were semi-conscious.
The Guardia Civil state that "the maintenance of appropriate air quality and quantity inside the vehicle for the species and number of animals transported was not guaranteed; furthermore, care was neglected during the journey". The company responsible for the transportation, Catalonia-based WeTravelHome, maintained that supervisory checks had been made during the ferry journey.
The 21-year-old driver of the vehicle and the person with legal responsibility at the company have been placed under investigation for negligence.
The dogs, all hunting dogs, and their owners had been in Lithuania for specialist training.