Authorities in both the U.S. and Spain have over recent days discovered dozens of kilograms of cocaine hidden inside shipments of pineapples originating from Costa Rica.

U.S. federal authorities on Wednesday last week seized around 45 kilograms (99 pounds) of the schedule 1 drug inside boxes of imported pineapples at the Port of Wilmington in Delaware, according to U.S. Customs and Border Protection (CBP).

It was a drug-sniffing dog at the port that first alerted authorities to the contraband, CBP said. They then begin searching loads of pineapples and discovered the drugs. 

"The cocaine was secreted within the corrugated bottoms of 20 cardboard boxes containing pineapples from San Carlos, Costa Rica," a CPB statement said. "The shipment was destined to Clifton, NJ."

The 45 kilograms of cocaine seized has a street value of about US$7.6 million.

A port worker told The News Journal that local police spent much of Thursday tearing through fruit boxes in search of additional shipments of illegal drugs. 

A photo of the searches showed fruit boxes marked with "Product of Costa Rica." 

More recently, Spanish police discovered more than 65kg of the drug stashed inside pineapples at a food market in Madrid, the Independent reported.

The bust was made by authorities at the MercaMadrid market in the Spanish capital, the second largest fish market in the world.

Police were filmed throwing pineapples on the ground and smashing them open to reveal cylinders of cocaine concealed inside.

The pineapples had reportedly been transported from Costa Rica to the Portuguese port of Setúbal before finally being brought to MercaMadrid.

According to investigators, the company that had imported the pineapples from Costa Rica had been using its imports as a cover-up in order to transport drugs into the European Union.