The majority of these calls originate from foreign-based gangsters or their associates, using Voice Over Internet Protocol or international phone numbers, they said.
Three of the four accused who were involved in the recent Rohini Court shootout in the national capital had planned to surrender before the judge after killing rival gangster Jitender Gogi, according to sources.
'As the firing started everything went haywire.'
A few days ago, the Crime Branch had taken jailed gangster Tillu Tajpuriya -- one of the prime conspirators -- in its custody to grill him about Gogi's killing.
Jailed gangster Tillu Tajpuriya, an accused in the Rohini court shootout, was killed in a morning attack by rivals inside Tihar Jail, officials said on Tuesday.
Jailed gangster Jitendra Gogi was shot dead on Friday inside Delhi's Rohini court by two killers dressed as lawyers.
The video, captured by a CCTV camera inside the high-security jail, showed the attackers descending from the first floor by clinging to bed sheets using them as a rope and then barging into Tajpuriya's cell on the ground floor to attack him.
Thirty-year-old Jitendra Mann 'Gogi', who was shot dead in a crowded Rohini court room on Friday, was one of Delhi's most wanted criminals and the chief of an "extremely sophisticated" organised crime syndicate.