4. LIABILITY TO TRIAL.

No person is liable to be tried or punished in Papua New Guinea for an indictable offence except under the express provisions of the Code or some other Act of the Parliament.

SCHEDULE 1 – THE CRIMINAL CODE.

PART I. – INTRODUCTORY.

Division 3. – Application of the Criminal Law.

11. EFFECT OF CHANGES IN LAW.

(1) A person cannot be punished for doing or omitting to do an act unless–

(a) the act or omission constituted an offence under the law in force when it occurred ; and
(b) doing or omitting to do the act under the same circumstances would constitute an offence under the law in force at the time when he is charged with the offence.

(2) If the law in force when the act or omission occurred differs from that in force at the time of the conviction, the offender cannot be punished to any greater extent than was authorized by the former law, or to any greater extent than is authorized by the latter law.

Article 22
Nullum crimen sine lege
1. A person shall not be criminally responsible under this Statute unless the conduct in question constitutes, at the time it takes place, a crime within the jurisdiction of the Court.
2. The definition of a crime shall be strictly construed and shall not be extended by analogy. In case of ambiguity, the definition shall be interpreted in favour of the person being investigated, prosecuted or convicted.
3. This article shall not affect the characterization of any conduct as criminal under international law independently of this Statute.