Match referee Rajendra Jadeja said that he has received a report from the umpires who changed the ball after warning Kartik.
"Yes I've received a report from the umpires who thought there were some issues with the ball and they warned the bowling team captain (Kartik) and the ball was changed," Jadeja said.
If such an incident further occurs then it would be case of ball tampering, Jadeja, of the Saurashtra CA, said.
A decision on whether to ban a player is taken by the Board's disciplinary committee, Jadeja said.
Bengal team manager Debabrata Das said his side noticed the incident just after lunch when Abhimanyu Easwaran was castled by Anureet Singh for a golden duck in the fifth over by a "reverse swing".
Leveling ball tampering charges against Kartik and pacer Anureet Singh, he said, "The ball started reversing from the fourth over which was just impossible. They were pricking the ball and coach Ashok Malhotra and I complained this to the Match Referee."
Just a month after both the teams were engaged in an ill-tempered match, triggered by a 'Mankading' incident by Kartik at league stage in New Delhi, Bengal and Railways renewed their bitter rivalry here once again.
