Dozens of kilograms of cocaine have been found in banana deliveries to four of a French supermarket chain’s stores, with police unsure who the intended recipient was.

Staff at Grand Frais branches in the Bourgogne-Franche-Comté region in eastern France were astonished to find between 40kg (88lb) and 50kg of drugs hidden under pallets of bananas and were anxious to reassure customers that the cocaine had not come into contact with the fruit.

Now detectives are attempting to solve the mystery of how the drugs, believed to have originated in Colombia, came to be in the pallets and – more importantly – for whom they were destined.