The arrested persons have been identified as Laxman Jaiswal, Ramesh Kumar Kashyap and Kumari Linge Tati -- all residents of the Dantewada district in Chhattisgarh.
The official said the agency found that Jaiswal, a grocery owner in Nakulnar, provided electric wires, explosives and other items for the IED blast carried out by CPI (Maoist) cadres.
Kashyap, ex-sarpanch of Kakadi village, and Kumari Linge Tati provided logistic support to the Maoists and were part of the conspiracy that led to the Mandavi's killing along with four security personnel of the Chhattisgarh Armed Force (CAF).
The accused, produced before the NIA Special Court in Jagdalpur on Wednesday, have been remanded to 7-day police remand.
They were killed in an explosion near Shyamgiri village under the Kuakonda police station. The security personnel's arms and ammunitions were also looted by the Maoists.
A case was registered under various sections of the Indian Penal Code, the Arms Act, the Explosive Substances Act and the Unlawful Activities (Prevention) Act, 1967.
Subsequently, the NIA registered a case on May 17, 2019. It arrested Bhima Tati and Madka Ram Tati, both residents of Dantewada, on April 4.