Five Egyptians and six Zambians appeared in court on Monday after a mystery plane landed in Lusaka with 130 kilos of "suspected" gold, nearly six million dollars and weapons on board.
Drug and law enforcement authorities said 11 suspects, including a senior Zambian police officer, had been arrested and charged with "espionage", in the capital.
The suspects arrived at a magistrate's court late Monday afternoon.
Authorities in the Southern African country seized 127 kilos of "suspected gold", a handful of firearms, 126 rounds of ammunition and almost $5.7 million when the plane landed in Lusaka two weeks ago.
The Drug Enforcement Commission said the chartered aircraft was transporting "dangerous goods".
Judge Davies Chimbwili said that they were accused of having acted "for purposes that were prejudicial to the safety and interest of the Republic of Zambia."
They were later taken into custody.
Court papers list a former Egyptian military person and businessman as well as a Zambian police officer among the suspects.
The story, much of which remains unclear, has continued making waves in Egypt.
An independent Egyptian journalist who was arrested in Cairo following reports accusing officials of involvement in smuggling cash, weapons and gold, was later released.
However, Egyptian state media had claimed the aircraft in question was privately owned and that it had only transited through Cairo.
The suspects could face up to 30 years in jail under Zambian law.