Robbers had looted passengers of the air-conditioned coach in the Kamayani Express on the Allahabad-Satna Rail Division on the border of Madhya Pradesh and Uttar Pradesh on the intervening night of 27-28 December.
Police sources said jewellery worth several lakh rupees, mobile phone and cash had been looted.
According to facts revealed during investigation carried out by the Government Railway Police of Madhya Pradesh, it appeared the dacoity was carried out by the Natthu Kol, who was a member of Shikumar Kurmi alias Dadua gang.
He had made phone calls with the looted mobile phone. Uttar Pradesh police has announced a reward of Rs 50,000 on the head of Natthu.
Dadua had been slain in a recent police encounter. About a dozen members of the gang were along with Natthu Kol, while the rest were with Dadua's main assistant Radhe Kurmi.
UNI XC-PS 1244