Part One
GENERAL PROVISIONS
Chapter II
FUNDAMENTAL PRINCIPLES
Article 24. Spoken and written language used in the criminal procedure
Spoken and written language used in the criminal procedure is Vietnamese. Participants in the criminal procedure may use spoken and written languages of their own nationalities; in this case, interpreters shall be required.
Fair trial standards
Rights during investigation - access to interpreter and translation if questioned in other language
Rights during trial - interpretation and translation
EDIT.