Anwar has reportedly gone into hiding after he was stopped from travelling abroad on Tuesday. He was offloaded at Benazir International Airport, Rawalpindi, from a Dubai bound international flight.
"It is confirmed that they are not in their homes and have been gone into hiding. It seems that they are all together but they are trying to dodge investigators by showing their mobile phone locations in various parts of the country," The Express Tribune quoted a senior official privy to the investigations as saying.
"But we are continuously trying to trace their locations. Besides taking technical assistance, we are also using our human intelligence network to trace and arrest them", the official added.
Rao Anwar and other officers are in the dock for killing at least four men during what they claimed was a raid on a suspected Taliban hideout in Karachi.
Relatives of one of the dead men, who was identified as Naqeebullah Mehsud, 27, from South Waziristan tribal district, rejected claims of him having militant links and maintained that he was an aspiring model who had been a resident of Karachi since 2008. They added that Naqeebullah was looking for a job and had been running a shop in the city.
His killing evoked a national outcry and triggered protest rallies in several cities. (ANI)