A stash of about 1,161 pounds of Papaver somniferum, also known as opium poppy, was seized in Spain./Spanish Civil Guard

Three men were arrested in Spain last month for allegedly shipping dried opium poppy capsules by mail across Spain and to the United States.

The Spanish Civil Guard said Saturday that the three men were arrested in January and have remained in custody since. They were charged with crimes against public health for drug trafficking.

According to police, the investigation began last September after four postal shipments containing nearly 15.4 pounds of plant-based substances were intercepted at the Alicante-Elche Miguel Hernandez Airport.

Analysis determined that the substance was "Papaver somniferum," also known as opium poppy, a plant directly linked to the production of opium and its derivatives, the statement said.

Investigators noted that the same surname was used on all the shipments, both for the senders and recipients. It was also verified that all the packages had been sent from different addresses, located in the municipality of Los Alcázares, in the Murcia region.

The operation led to the identification of three men from the same clan, all born in India, who were arrested and a stash of about 1,161 pounds of Papaver somniferum was seized.

After consulting police databases, investigators verified that the three men had been linked to recent thefts of opium poppy from legal plantations intended for pharmaceutical use and located in the province of Albacete.

"In Spain, there are legal crops of this plant intended for pharmaceutical use," said Guardia Civil spokesman Álvaro Gallardo. "But there are many people who extract opium completely illegally for consumption or trafficking, something dangerous if done uncontrollably, since it is a narcotic substance."

The three detainees were brought before the investigating court of the judicial district of Elche, which ordered their imprisonment.