A three-member Appellate Division bench, led by Chief Justice Syed Mahmud Hossain passed the order after rejecting the two separate petitions filed by the state.
Barrister Moudud Ahmed stood for the BNP leader while Attorney General Mahabubey Alam represented the state.
Earlier on September 27, the High Court granted anticipatory bail to Amir Khasru Mahmud Chowdhury in the two cases.
An HC bench of justice Muhammad Abdul Hafiz and justice Bhishmadev Chakrabortty passed the order after the BNP leader surrendered before the court and prayed for bail in the cases.
Of the cases, one was filed with Shahbagh police station in the capital and the other with Kotwali police station in Chattogram on August 4.
Khasru was sued as a reported audio clip of his telephonic conversation with a youth over intensifying the recent student movement went viral on Facebook and YouTube on August 4.