Authorities in Mali say they began an inquiry into the violation of state security on Monday.
It comes after six prominent figures were detained for questioning earlier this month.
It also follows the August 18 coup which ousted longtime leader President Ibrahim Boubacar Keita and put the country in the hands of a transitional government scheduled to oversee a return to civilian rule within 18 months.
The public prosecutor in the capital Bamako said a “preliminary inquiry” had been launched by judicial investigators “following a report by the security services relating to violations of state security”.
The most prominent person arrested was radio broadcaster Muhammad Yusef Batheili -known as “Ras Bath”, he is a popular figure with young Malians
The half brother of former Prime Minister Cisse-- Aguibou Tall-- and the secretary of the president’s office, Sekou Traore, were also detained, according to security sources.
Before their arrest, it was said there was a scheme to “destabilise” transitional institutions set up after the coup.
Cisse has denied any involvement in such schemes.
His home in Bamako was searched by unidentified men on December 24, his lawyers said.