CHAPTER 11:24
MUTUAL ASSISTANCE IN CRIMINAL MATTERS ACT
PART III
REQUESTS BY COMMONWEALTH COUNTRIES TO TRINIDAD AND TOBAGO FOR ASSISTANCE
22. Acceptance or refusal of request, etc.
(2) Such a request shall be refused if, in the opinion of the Central Authority—
(f) the request relates to conduct by a person that constitutes an offence in respect of which the person has already been convicted or acquitted by a Court or tribunal in Trinidad and Tobago ;
Ne bis in idem
Ne bis in idem - ICC
EDIT.