DCI detectives are at this hour interrogating Pokot South MP David Pkosing over the banditry menace in the region.
He was arrested Thursday evening as he was leaving his office at KICC.
Several MPs from West Pokot trooped to the DCI headquarters along Kiambu road in solidarity with the lawmaker.
They include Senator Julius Murgor, Woman Rep Rael Leotum, Sigor MP Peter Lokachapong, North Pokot MP Titus Lotee and Kapenguria MP Samuel Moroto.
The government has declared total war on banditry in six hotspot counties where a combined security operation comprising the police and military has been ordered.
Interior CS Kithure Kindiki revealed on Sunday that in the last six months alone, more than 100 civilians and 16 police officers have been brutally murdered by marauding bandits and livestock rustlers in the Northern Rift Valley region.
The CS imposed a 30-day dusk-to-dawn curfew in some of the areas affected by banditry in the counties of Turkana, West Pokot, Elgeyo Marakwet, Baringo, Laikipia and Samburu as a corrective and deterrent measure.
The government also gave a three-day amnesty for voluntary surrender of all illegal firearms.