Yankuba Badjie headed the National Intelligence Agency during Jammeh's rule.
Gambian police have arrested ex-president Yahya Jammeh's dreaded former spy chief, a police source told AFP on Tuesday, following allegations of torture and disappearances during his watch.
Yankuba Badjie headed the National Intelligence Agency, which rights groups say carried out arbitrary detentions, forced disappearances and torture during Jammeh's 22-year rule.
The source said Badjie was in police custody and was "being investigated for certain things that happened during his stint at the NIA".
The source, speaking on condition of anonymity, said the arrest was made on Monday.
The Gambia's new President Adama Barrow has promised to reform the NIA - changing its name, replacing its chief and promising training for staff whose work would be limited to "intelligence gathering, analysis and advice to the relevant arms of government".
Gambian police on Tuesday brought criminal charges against 25 supporters of Jammeh's Alliance for Patriotic Reorientation and Construction Party, over attacks on Barrow supporters earlier this month.