Constitution of Bangladesh
PART III - FUNDAMENTAL RIGHTS
Safeguards as to arrest and detention
33. (1) No person who is arrested shall be detained in custody without being informed as soon as may be of the grounds for such arrest nor shall he be denied the right to consult and be defended by a legal practitioner of his choice.
Fair trial standards
Rights during investigation - arbitrary arrest or detention and deprivation of liberty
Rights during investigation - informed of belief that crime has been committed
Rights during investigation - legal assistance
Rights during trial - counsel of accused's choosing
EDIT.