Police in Spain have arrested a yet to be identified Nigerian, along with five Colombians, five Spaniards and a Peruvian, in connection with a cocaine laboratory in the country.

They were arrested in Spanish cities of Madrid, Almeria, Toledo and Cadiz after months of surveillance.

It was the first time that the Spanish police would uncover such a laboratory within the country.

The police said that they have dismantled the cocaine laboratory similar to those found in Colombia and smashed the smuggling ring with the arrest of 12 people, including a Nigerian.

The ring is suspected of smuggling “signficant quantities” of cocaine mixed with palm kernel meal, a vegetable substance used for animal feed, from South America into Spain, police said in a statement.

The gang then used chemicals at the secret lab in Nijar, a quiet town of white-walled houses and narrow streets in the southwestern region of Andalucia, to extract the cocaine from the mix.

“It is the first time that a lab has been dismantled in Spain that used practices similar to those used by drug trafficking organisations in laboratories in the jungle in Colombia, where an alkaloid is extracted from the coca leaf and then processed,” the statement said.

Police said the man charged with processing the substance at the laboratory was a Colombian national known as “El quimico” or “The chemist”.

The authorities also seized 229 kilos (504 pounds) of cocaine as well as several weapons and chemicals used in the lab to extract the cocaine.

Police said they opened their investigation in December 2013 after being tipped off by authorities in the United States and Colombia that a group of Colombian origin would try to bring a large shipment of cocaine into Spain.

Spain’s proximity to north Africa, a major source of hashish, and its close ties with its former colonies in Latin America, a key cocaine-producing region, have made it the main gateway into Europe for drug traffickers.

The amount of cocaine seized in Spain rose 28.6 percent last year to 27 tonnes, according to interior ministry figures.

In January 2011, Spanish police arrested 25 people and dismantled what they claimed then was the biggest and most sophisticated cocaine laboratory known to date in Europe.

A police statement said agents seized about 300kg of the drug and 33 tonnes of chemicals used to prepare it for sale. Also confiscated were 470 mobile telephones and €2m (£1.7m) in cash in the raid, on a villa outside the capital, Madrid.

Those arrested then were Spanish and Colombian, including several Spanish lawyers suspected of helping to launder money made from the sale of the cocaine.

Police said the operation followed two years of investigations.