The former head of the Guinean armed forces is among 20 people expected to appear in court charged with drug trafficking in the next few days.
State media said they were arrested after months of investigations carried out by the new military authorities.
They include the former army chief, General Diarra Camara, his son, and other ex-senior officers.
Eight Nigerians, a Ghanaian and an Israeli are also among those reported to have been charged.
In recent years, West African countries such as Guinea have become major transit points in the trafficking of narcotics, particularly cocaine from Latin America.
The BBC's Alhassan Sillah in the capital, Conakry, says the start of the trial against the alleged drug traffickers will mark a significant turning point in the war waged against them by the military government led by Moussa Dadis Camara.
Capt Moussa Dadis Camara took power in a bloodless coup in December
It took power on the death of President Lansana Conte in December last year.
In addition to Gen Diarra Camara, the Guineans being held have been named as his son, Lt Amara Camara; an ex-head of the Marine Corps, Aly Daffe; and the officer who until his arrest was the serving head of the Marine Corps, Mohamed Camara.
In February, Ousmane Conte, the son of the former president, admitted on state television to drug trafficking.