Akhil's cousin Ashish Gupta has lodged an FIR against 2 unidentified persons, Senior Superintendent of Police H N Singh said.
Three teams led by SP, city, Sarvan Kumar have been formed to trace the accused, he said.
Police are investigating various angles including whether the murder was linked to Asaram's case or it was a fallout of old enmity, officials said.
Akhil was returning home from his shop on a scooter when the two motorcycle-borne assailant shot at him. He was declared dead in district hospital last evening.
Gupta was a cook and personal aide of self-styled 'Godman' Asaram, who is in jail since September 2013 in connection with another case of sexual assault on a minor girl in Jodhpur.
Two sisters in Surat have accused Asaram and his son Narayan Sai of raping them. Gupta was a witness in the rape case against Asaram and had recorded his statement before a Gandhinagar court.
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