SIT officials apprehended Suresh, an associate of suspended CI SSVV Nagaraju, in Bengaluru.
The investigation centers on the alleged disposal of Saikrishna's body after his death in police custody.
Special teams are actively searching for absconding head constables Ashok and Jangam Nani.
Authorities are probing potential conspiracies to destroy evidence and the role of mediators in the case.