The police investigation is underway pertaining to the sensational murder case of the former MP YS Vivekanand Reddy. Police team members of SIT have questioned so far 20 suspicious persons at a secret place in Kadapa. Police have also questioned the family members of late YS Vivekanand Reddy at DSP office in Pulivendula. YS Vivekananda Reddy's daughter Sunitha has admitted before the police that the letter found near the murder incident area belongs to her father's handwriting only. YS Vivekananda Reddy's close associate Erra Gangireddy, driver Prasad, PA Krishna Reddy, maid Lakshmi and others were interrogated as part of the investigation.