91. (1) No trial by court martial of any person subject to this Act for any offence, other than an offence of desertion or fraudulent enrolment or any of the offences mentioned in section 31 or section 40, shall be commenced after the expiration of three years from the date of such offence and no such trial for an offence of desertion, other than desertion on active service or of fraudulent enrolment shall be commenced if the person in question, not being an officer, has subsequently to the commission of the offence, served continuously in an exemplary manner for not less than three years with any portion of the Bangladesh regular forces. (2) In the computation of the period of three years specified in sub-section (1) any time spent by the person in question as a prisoner of war, or in evading arrest, shall be excluded.