Person surrendered by Commonwealth country in respect of an offence not to be prosecuted or detained for other offences
31.  Where a person accused or convicted of an extraditable crime is surrendered by a declared Commonwealth country, the person shall not, unless he has been returned, or has had an opportunity of returning, to that country —
(a)be detained or tried in Singapore for any offence that is alleged to have been committed, or was committed, before his surrender other than —
(i)the offence to which the requisition for his surrender relates or any lesser offence of which he could be convicted upon proof of the facts on which that requisition was based; or
(ii)any other extraditable crime in respect of which that country consents to his being so detained or tried, as the case may be; or
(b)be detained in Singapore for the purpose of his being surrendered to another country for trial or punishment for any offence that is alleged to have been committed, or was committed, before his surrender to Singapore other than —
(i)a lesser offence of which he could be convicted upon proof of the facts on which the requisition referred to in paragraph (a) was based; or
(ii)any other offence in respect of which the country by which he was surrendered to Singapore consents to his being so detained.