Dhoni had been informed of the ban verbally, BCCI vice president Rajiv Shukla confirmed. The rest of the Indian players were fined 40% of their match fee for the offence.
"We have received information that the match referee has put a two-ODI ban on Dhoni for slow over-rate," Ratnakar Shetty, BCCI's chief administrative officer, said. "We are waiting for a formal communication on this. We will look into details and then make further comments."
The second ODI ended about 45 minutes after the scheduled finish time because of frequent discussions between the Indian players during the closing stages of Sri Lanka's chase. The visitors won the game by three wickets to level the five-match series 1-1. The decision to ban Dhoni was taken by match referee Jeff Crowe.
Sri Lanka were penalised for their slow over-rate during the second Twenty20 international against India in Mohali after falling two overs short of their target. The captain Kumar Sangakkara was fined 40% of his match fee while the rest of the team was docked 20% each. Crowe said Sangakkara just escaped a much bigger penalty.