The Europol supported operation uncovered and seized €650, 000 worth of illegal substances, with 41 individuals being arrested.
In total 112 types of illegal substances were seized, which included four million doses of anabolic steroids, hormones, sexual enhancers and other substances.
Anabolic steroids, or anabolic androgenic steroids (AAS), are mainly used to help build muscles and improve sports performance.
By producing a synthetic version of testosterone in the body they allow individuals to train harder and for longer periods of time.
However, AAS are associated with severe side effects including liver damage, kidney damage and heart muscle thickening.
For this reason, they are now illegal for commercial sale, in most European countries, without a doctor’s prescription.
Furthermore, all major sports bodies also ban the use of AAS, including Association of Tennis professionals, Major League Baseball, Fédération Internationale de Football Association, the Olympics, the National Football League and the National Basketball Association.
Large-scale crime organisation
According to Europol, the investigation took place in four phases, after beginning in early 2017, over various Spanish regions and included 45 searches of homes, stores and gyms.
Elite athletes, international bodybuilding and fitness champions are amongst those arrested.
Luxury vehicles, cash, weapons and narcotic substances, including cocaine, were also seized during the operation.
The investigation began after a sports centre in the Balearic Islands was found to be trading illegal substances without medical checks.
Authorities uncovered that these substances had been imported from Portugal to be commercially sold across Spain.
Europol deployed eight specialists to Spain during the investigation to help the local authorities with the task.
The crime group has now been totally dismantled, according to Europol.
Hidden parcels
It is believed that the crime group shipped the illegal substances to Spain from other countries including Bulgaria, Greece, Hungary, Latvia, Poland, Portugal and the United States.
The investigation revealed that between 2016 and 2017, the group made 4,400 shipments of parcels weighing approximately 3.1 tonnes in total, and possibly earned €2m in illegal profits.
The group used false identities, hidden packages, and commercial structures in order to ship the illegal substances from country to country.
Last week, three suspects were detained in the Netherlands for the illegal sale of AAS.