War Crimes are crimes that come under the collective name of core international crimes. Core international crimes are some of the gravest crimes in international law, examples of them can include: the crime of genocide, crimes against humanity, war crimes and torture. 

Through international treaties the UK has a responsibility to investigate and prosecute those who have committed core international crimes.

Alternatively, there may be those in the UK who have witnessed offences or are survivors of such crimes.

If a UK resident has been responsible for core international crimes anywhere in the world, they may be investigated and prosecuted in the UK.

Examples of core international crimes can fall under the four different groups listed below.  

Violations of the laws or customs of war, including:

  • atrocities or offences against persons or property, constituting violations of the laws or customs of war
  • murder, ill treatment or deportation to slave labour or for any other purpose of the civilian population in occupied territory
  • murder or ill treatment of prisoners of war or persons on the seas
  • killing of hostages
  • torture or inhuman treatment, including biological experiments
  • breaches of the Geneva Conventions.
  • plunder of public or private property
  • wanton destruction of cities, towns or villages
  • devastation not justified by military necessity
  • destruction of property that is of particular cultural significance

It is an offence for a public official or person acting in an official capacity to intentionally inflict severe pain or suffering on another in the performance or purported performance of their official duties, without lawful authority.

Genocide is a crime under international law even if it is not a crime in the country where it takes place, and incitement to commit genocide is also a crime.

Genocide means any of the following acts committed with intent to destroy, in whole or in part, a national, ethnic, racial or religious group:

  • killing members of the group
  • causing serious bodily or mental harm to members of the group
  • deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part
  • imposing measures intended to prevent births within the group
  • forcibly transferring children of the group to another group

Atrocities and offences committed against any civilian population, as part of a widespread attack, including:

  • murder
  • extermination
  • enslavement
  • deportation
  • mass systematic rape and sexual enslavement in a time of war
  • other inhumane acts
  • persecutions on political, racial or religious grounds in execution of or in connection with any other crime against humanity

Report it

If you have been a victim of or witness to core international crimes, please let us know. Your information could be vital to an investigation in the UK or another part of the world.

You can also help by providing information that identifies perpetrators of core international crimes living in this country and the crimes they may have committed.

We will treat all of the information you provide in the strictest of confidence.

If you have information that you think can assist us, you can contact the War Crimes Team in any of the following ways: 

You can contact the War Crimes Team at The Met online.

If you want to report anonymously, you can contact Crimestoppers, either online or on their free helpline 0800555111.

For further information on the criteria we use to scope referrals, please see the Crown Prosecution Service: war crimes/crimes against humanity referral guidelines

Further advice and support

We understand that you may not be ready to talk to us about what has happened. The charities, groups and organisations below can offer support, advice and ways to report the incident without having to talk directly to the police. They can pass your information to us and preserve your anonymity.

Our partners may also be able to consider other action against suspected perpetrators, if a criminal prosecution is not possible.

The following organisations attend meetings of the UK War Crimes Network with police and government agencies. They work to deliver justice for survivors of core international crimes.


Redress seek justice and reparation for survivors of torture, combat impunity for perpetrators, and develop and promote compliance with international standards.

Amnesty International

Amnesty International investigate and expose human rights abuses around the world, and campaign to end such abuses.

Human Rights Watch

Human Rights Watch investigates and reports on abuses happening in all corners of the world.

Open Society Justice Initiative

The Open Society Justice Initiative uses the law to promote and defend justice and human rights.

Helen Bamber Foundation

The Helen Bamber Foundation supports refugees and asylum seekers who have experienced extreme human cruelty, such as torture and human trafficking.

Freedom from torture

Freedom from torture provides specialist psychological therapy to help asylum seekers and refugees who have survived torture, recover and rebuild their lives in the UK.

More information on the investigation and prosecution of core international crimes around the world can be found on the websites of these organisations:

International Criminal Court

The International Criminal Court (ICC) investigates and tries individuals charged with core international crimes. As a court of last resort, it seeks to complement, not replace, national Courts.

International, Impartial and Independent Mechanism for Syria (IIIM)

The IIIM was set up to assist in the investigation and prosecution of those responsible for the most serious crimes under international law committed in Syria since March 2011. It aims to collect, preserve and analyse evidence of such crimes, and to prepare files in order to assist future prosecutions in national, regional or international courts.

United Nations Investigative Team to Promote Accountability for Crimes Committed by Da’esh/ISIL (UNITAD)

Between June 2014 and December 2017, ISIL captured and controlled large swathes of territory in Iraq, committing grave abuses of international law. UNITAD is an investigative team that aims to support domestic efforts to hold ISIL accountable by collecting, preserving and storing evidence of acts that might amount to war crimes, crimes against humanity and genocide committed in Iraq.


Europol aims to facilitate the cooperation and coordination of EU Member States and Third Parties’ efforts to identify and investigate individuals, networks and groups involved in committing core international crimes through its Analysis Project (AP CIC).


Eurojust hosts the annual EU Genocide Network, to enable close cooperation between national authorities when investigating and prosecuting core international crimes. The Network’s mandate is to ensure perpetrators do not attain impunity within the Member States.