United Kingdom of Great Britain and Northern Ireland
PART 5 Offence under Domestic Law
England and Wales
51 Genocide, crimes against humanity and war crimes
(1) It is an offence against the law of England and Wales for a person to commit genocide, a crime against humanity or a war crime.
(2) This section applies to acts committed—
(a) in England or Wales, or
(b) outside the United Kingdom by a United Kingdom national, a United Kingdom resident or a person subject to UK service jurisdiction.
52 Conduct ancillary to genocide, etc. committed outside jurisdiction
(1) It is an offence against the law of England and Wales for a person to engage in conduct ancillary to an act to which this section applies.
(2) This section applies to an act that if committed in England or Wales would constitute—
(a) an offence under section 51 (genocide, crime against humanity or war crime), or
(b) an offence under this section,
but which, being committed (or intended to be committed) outside England and Wales, does not constitute such an offence.
(3) The reference in subsection (1) to conduct ancillary to such an act is to conduct that would constitute an ancillary offence in relation to that act if the act were committed in England or Wales.
(4) This section applies where the conduct in question consists of or includes an act committed—
(a) in England or Wales, or
(b) outside the United Kingdom by a United Kingdom national, a United Kingdom resident or a person subject to UK service jurisdiction.
53 Trial and punishment of main offences
(1) The following provisions apply in relation to—
(a) offences under section 51 (genocide, crimes against humanity and war crimes),
(b) offences under section 52 (conduct ancillary to genocide, etc. committed outside jurisdiction), and
(c) offences ancillary to an offence within paragraph (a) or (b) above.
(2) The offence is triable only on indictment.
(3) Proceedings for an offence shall not be instituted except by or with the consent of the Attorney General.
(4) If the offence is not committed in England or Wales—
(a) proceedings may be taken, and
(b) the offence may for incidental purposes be treated as having been committed,
in any place in England or Wales.
(5) A person convicted of—
(a) an offence involving murder, or
(b) an offence ancillary to an offence involving murder,
shall be dealt with as for an offence of murder or, as the case may be, the corresponding ancillary offence in relation to murder.
In this subsection “murder” means the killing of a person in such circumstances as would, if committed in England or Wales, constitute murder.
(6) In any other case a person convicted of an offence is liable to imprisonment for a term not exceeding 30 years.
Crimes against humanity
Genocide
War crimes
EDIT.