The outgoing cricket chief withdrew from his re-election bid last month as he faced charges of helping a noted criminal to travel abroad on a forged passport and watch a cricket match in England.
Sumathipala has been remanded into custody pending further police investigations.
"We have decided unanimously to name Mr Sumathipala as the representative of Sri Lanka Cricket at international events," the new cricket chief Mohan de Silva said.
Sumathipala will also be Sri Lanka's nominee to the International Cricket Council. He is also the chairman of Sri Lanka Telecom, the main carrier partly owned and fully managed by NTT of Japan.
Sumathipala had been accused of aiding and abetting Dhammika Amarasinghe, a man implicated in more than 28 murder cases and with previous convictions, to obtain a forged passport and travel to London.
Amarasinghe was shot dead in January as he was escorted to court in connection with an unrelated case by a gunman disguised as a lawyer.