Bangladeshi officials say the country's central bank is investigating suspicious bank transactions to identify where Islamist militants are getting their money.
Central Bank officials said on Wednesday they are looking into several accounts at the Sylhet branch of the Islami Bank Bangladesh.
Islami Bank officials were not available for comment.
Officials launched the probe after finding bank documents at the house of the leader of the banned group Jamayetul Mujahedin Bangladesh.
Police arrested the militant leader, Shaikh Abdur Rahman, in the northeastern city of Sylhet earlier this month.
Rahman has confessed to masterminding a string of bombings that killed more than 25 people across the country last year.
The banned group wants strict Islamic laws to be implemented in mostly-Muslim Bangladesh, which has a secular constitution.