In any prosecution under this Part, any participant in a violation of this Part, when requested by the district attorney, commissioner or other officer instituting the prosecution, may be compelled to testify as a witness against any other person charged with violating this Part, but the evidence given may not be used against the person testifying in any prosecution for such a violation.   [PL 2003, c. 614, §9 (AFF); PL 2003, c. 655, Pt. B, §61 (AMD); PL 2003, c. 655, Pt. B, §422 (AFF).]