An attempt to smuggle over half a ton of spoiled fish into Israel could have ended in a mass poisoning, health inspectors said on Tuesday.

Naval police and customs officers boarded a ship sailing under a foreign flag as it entered Israeli territorial waters from Jordan. The vessel’s Israeli owner, who lacked the proper sailing certificates, declared he carried no cargo. After the officers discovered a large load of polystyrene boxes containing fish in the ship’s holds, the man claimed to have caught the fish himself.

Police docked the ship in the Eilat port, waiting for health inspectors to arrive, as food imports must receive Health Ministry permits. The owner, disobeying police orders, then attempted to escape toward the Eilat marina, where the vessel was stopped by the Border Patrol’s maritime unit.

When health inspectors checked the cargo, it became apparent the man tried to sneak in in 560 kilograms of porgies without paying the customs duty. The investigation showed the fish were bought in Suez, Egypt, and were seven days past their expiration date — posing a major health threat if the owner’s suspected intention of selling the fish to hotels and restaurants had been successful.

Police destroyed the fish, and opened a criminal investigation against the ship owner on counts of smuggling and disobeying a police order.