Good, Bad, Ugly - Part 2

The STF interrogates Varadharajan, Sargunam's brother, and finds out that Sargunam shared a great bond with his brother's family. The interrogation reveals that after Sargunam's wife passed away, Varadharajan had taken control of his entire business, making DSP Kadhir feel suspicious about the whole turn of events. Soon, Kadhir finds out the real culprit. Who is it?