ESPNcricinfo has learned that Shanto sent the message to senior board officials following the first Test against South Africa in Dhaka, which Bangladesh lost by seven wickets. The BCB is yet to discuss the matter as president Faruque Ahmed is not in the country - he is expected to arrive in Dhaka on Monday evening.

If Shanto's resignation is accepted, the BCB will have to appoint a new captain on short notice with a packed schedule ahead.

The second Test against South Africa is scheduled for October 29 to November 2, and Bangladesh are then off to the UAE to play three ODIs against Afghanistan, with the first game on November 6. That series ends on November 11, and they then go to the West Indies for an all-format series - the three-day tour match prior to the series-opening first Test starts on November 15.

ESPNcricinfo understands Shanto's fluctuating form with the bat influenced his decision. He has averaged 25.76 since taking over the Test captaincy last November after being one of the team's in-form batters at the time.

He was subsequently given Bangladesh's ODI and T20I captaincy too, as the BCB was looking for a man to lead the team through the period of transition with several of their senior cricketers either retiring from certain formats or being on the verge of doing so.