Colonel Moussa Keita, an ally of Camara, was stopped “by people in civilian clothes” while in traffic, and was told to get into their truck, a family member said on condition of anonymity.
He was later taken to army headquarters and then to an unknown destination.
“Since then we have not been able to contact him, but his driver came back very dirt with his shirt completely torn,” another family member said.
Keita was the permanent secretary of the political wing of a military junta which took power in December 2008 when longtime ruler Lansana Conte died.
In recent weeks Keita has made statements to local media accusing General Sekouba Konate – head of a transition government put in place after Camara was shot by a close aide – of embezzling $20million.
Konate is hailed as leading the poor West African nation to its first democratic vote in half a century, in which Alpha Conde was declared president in November 2010.