Libya's chief prosecutor had sought Khazimi with a warrant since 2017.
Libyan authorities said Tuesday that government forces have arrested a senior Islamic State group (IS) figure in an operation south of the capital Tripoli.
Prime Minister Abdul Hamid Dbeibah of the North African country's interim government wrote on Twitter that the capture of Embarak al-Khazimi was "a great success for our security forces".
Libya's chief prosecutor had sought Khazimi
Read full articlewith a warrant since 2017.
His arrest "will allow us to gather vital information about IS and bring a dangerous terrorist to justice", Dbeibah added.
Forces from the interior and defence ministries had earlier announced Khazimi's arrest at Bani Walid, around 170 kilometres (105 miles) from Tripoli on the northern fringe of the Libyan desert.
Plunged into chaos in 2011 when Moamer Kadhafi's regime collapsed, Libya has been divided between rival power centres and torn by bloody conflict involving militias, foreign fighters and jihadist groups.
IS jihadists set up base in the towns of Sirte and Derna before being driven out in 2016 and 2018.
The group's members are now holed up in the desert or hiding among the population along the coast, but remain a threat to the country and its neighbours.
