Mr Ganapathy was found dead in his hotel room on July 7 last year, soon after giving an interview to a local Kannada news channel, in which he alleged the then Home Minister KJ George and two senior IPS officers Pranob Mohanty and AM Prasad had harassed him.
The state Criminal Investigation Department (CID) had given a clean chit to all three.
Unhappy with the CID probe, Mr Ganapathy's family approached the Supreme Court, which has directed the CBI to probe the case.
The CBI, which began its investigation recently, recovered a bullet yesterday in the hotel one-and-half years after the incident.
"The recovery of another bullet shows how the investigation was done and how attempts were made to hush-up the case," he alleged.
Ever since the supreme court directed the CBI to investigate the case, the BJP has been demanding that chief minister Siddaramaiah should remove Bengaluru Development Minister KJ George from his cabinet.
However, Mr Siddaramaiah has rejected the demand.
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.