The National Investigation Agency (NIA) on Saturday took over the investigation of the case involving Davinder Singh, who was arrested last week while travelling with self-styled Hizbul Mujahideen commander Naveed Babu, his accomplice Rafi and a lawyer, Irfan Mir.
The four were nabbed by the Jammu and Kashmir Police from a car near Qazigund on the National Highway in south Kashmir.
Singh, who was stripped of the Sher-e-Kashmir Police Medal and also suspended from service earlier this week, was purportedly ferrying Babu to Jammu.
In the raids that followed the arrest, arms and ammunition were recovered at the residences of the disgraced deputy superintendent of police in Srinagar.
The NIA re-registered the case and started the probe after receiving orders from the Union Home Ministry.
The Jammu and Kashmir government had stripped Singh of the Police Medal for Gallantry on Wednesday. The medal was awarded to him on August 14, 2018.
The Congress had on Friday called for a fair investigation into the case within six months and Mr. Rahul Gandhi had alleged that the case was handed over to the NIA to 'silence' Singh.