A court in Bengaluru has remanded a young engineer behind a popular pro-Islamic State (IS) Twitter account into five-day police custody.
"Bengaluru CCB Police have got five days police remand (till December 18) of Mehdi Masroor Biswas. He was presented before the magistrate last (Saturday) night," deputy commissioner of police (crime) Abhishek Goyal said.
Meanwhile, there were reports that police received a few threat calls following Biswas's arrest on Saturday.
A tweet from an unknown Twitter account (@abouanfal6) threatened Goyal of revenge.
@goyal_abhei we will not leave our brothers in your hand Revenge is coming wait for our reaction— abouanfal almaghribi (@abouanfal6) December 13, 2014
Goyal said he had forwarded the tweet to the cyber crimes wing of the crime branch for tracing its origin and the handler behind it.
"I have informed my senior officers about the threat message, though I am not giving much importance or taking it seriously," he said.
Britain's Channel4 revealed Wednesday night Biswas as the man behind the Twitter handle @ShamiWitness that was described as a "leading conduit of information between jihadis, supporters and recruits" with 2 million views each month.
A police team raided Biswas' one-room apartment in the northern suburb early Saturday and arrested him.
The mobile phone - the one that he apparently used to tweet thousands of jihadi posts to his 17,000 followers on Twitter - was confiscated along with a laptop and other documents for evidence.
After preliminary investigations, police had said 24-year-old Mehdi, a resident of a Kolkata suburb who is working with ITC in Bengaluru, probably didn't have any direct links with the Sunni terror group which controls swathes of Syria and Iraq and aims to create an Islamic caliphate.
Police have registered a case against Biswas under sections of the Indian Penal Code (IPC), the Unlawful Activities (Prevention) Act and the Information Technology (IT) Act.
"We are quizzing him on his virtual and actual relations with the terror group and checking his antecedents, including mobile calls, e-mails, chat sessions and postings in the social media like Facebook, blogs and Twitter," additional director general of police Hemant Nimbalkar told reporters.
Investigators are looking into "every possible" connection between Biswas and the IS, he added.
Probe has revealed Biswas was a propagandist of IS ideology and "has been instrumental in influencing minds against our friendly nations against whom IS is at war".
Nimbalkar said the investigation team was also looking into presence of any of the domestic connect or sleeper cell in India. "The follower network is being studied."
(with PTI and IANS inputs)