The officials said that an IPDR analysis would be carried out on their phones to check their activities on the Internet.
The president of the Kanpur chapter of the Sufi Khanqah Association, Mohammad Kausar Hasan Majeedi, has sought a probe into the operations of Dawat-e-Islami in Kanpur.
Udaipur murder: Pakistan-based Dawat-e-Islami comes under scanner for fund collection near border areas
Also, an instance of a politician from the desert state allegedly donating about Rs 2 lakh to the organisation is under the radar of agencies probing the case.
Riaz Akhtari, seen killing the tailor in a grisly video clip, used to work as a welder, while his accomplice Ghouse Mohammad took up petty jobs for a living, police sources said on Wednesday.
The police have detained three more people in connection with the killing so far.