Selected provisions from Geneva Law that emphasise the humane treatment of detainees during an international armed conflict are reviewed. The legal vagaries of a non-international armed conflict (NIAC) are considered in the Iraq context following the judgement in Serdar Mohammed and Secretary of State for Defence that questioned the legal basis for detention in an NIAC. The factors and thresholds of prevalent alleged offences are analysed by reference to the International Criminal Court ‘Elements of Crime’ and international jurisprudence. The incongruent or complementary status of international humanitarian law and international human rights law, including lex specialis, is considered by reference to international and European jurisprudence. The importance of the UN Torture Convention is highlighted and contextualised with regard to domestic legislation and government policy.