Sandip Ghosh was asked to furnish details of the phone calls he made before and after the incident at the hospital, an officer of the central probe agency said.
There is speculation that the former Jharkhand CM may meet Amit Shah to discuss joining the BJP; Soren also updated his profile on 'X' to remove references to JMM.
In a communication to the state police forces, the home ministry said that the law and order situation of all states should be monitored in view of the protests.