Vijay Kumar Mishra, a constable was killed in September last year over a property dispute related to the ownership of Bhupati Bhawan, which is also the crime scene, Superintendent of Police Heera Lal said.
In this connection, an FIR was registered against hundreds of persons including, Anant, he said.
Anant was arrested from the Bhawan, whose ownership of which is being claimed by several people of the Amethi's royal family.
A local court had also issued a non-bailable warrant against him, the SP said.