The six, including 'zonal commander' of CPI(Maoist) Bhushan Sharma were arrested when the police raided several places in Rampur on Dec 25.
Besides Sharma, the others netted by the police are CPI(Maoist) 'regional commander' Suresh Yadav alias Chandanji, 'area commanders' Jainandan Paswan, Jitendra singh and Arjun Paswan and secretary of the outfit's zonal sub-committee Yugal Yadav.
The arrested Maoist leaders were involved in the killing of a station house officer Mithilesh Prasad in Gaya and 45 other naxal related incidents in Bihar and Jharkhand, Kumar said.
One AK-56 rifle, two regular carbines looted from police, two country-made pistols, 249 live cartridges besides Rs 59,000 in cash and seven mobile phones were seized from them, he added.
(With inputs from PTI)