Human rights lawyers have outlined allegations by hundreds of Iraqis that they were mistreated by British forces.
More than 400 claims by Iraqis are now being presented in a dossier to the International Criminal Court.
Alleged abuses include sleep and food deprivation, physical assault, electrocution, mock executions and threats of rape.
Britain's Ministry of Defence has issued a statement saying the matters are under thorough investigation. It also rejected claims that the UK's armed forces systematically tortured detainees.
Al Jazeera's Emma Hayward reports from London.
WARNING: You may find some of the images in this report disturbing.