Inquiry began on Saturday into the derailment of New Delhi-Dibrugarh Rajdhani Express near Goldenganj station here on the wee hours of Wednesday that left four dead and 23 others injured.
Railway Safety Commissioner, Eastern circle, Kolkata, PK Vajpayee inspected the tracks and its nearby area as part of the probe. While talking to reporters, Vajpayee did not rule out Maoist hand in the tragedy but said it could be confirmed only after the inquiry.
It would take at least a month for the probe report to come, the Rail Safety Commissioner said.
After inspecting the track, he went to Sonepur division headquarters and interacted with people and officials to gather details about the derailment in which 12 coaches either derailed or overturned on June 25.
Chief Public Relations Officer, East Central Railway, Arvind Kumar Rajak said the probe officer would come again on July one for the inquiry.
Divergent views have been expressed by the railways and Bihar government on the cause of the derailment. While railways alleged sabotage by Maoists, the state government blamed error by Railways as the reason for the tragedy.