British troops breached the Geneva Conventions by subjecting Iraqi civilians to cruel and inhuman treatment, the High court ruled on Thursday.
Mr Justice Leggatt ruled that British soldiers took turns in running over the backs of detained civilians and hooding them for long periods of time.
The judgement came as a result of two High Court civil trials in which four Iraqi civilians claimed they had been subjected to unlawful detention and abuse by British forces.
Geneva Conventions apply in times of armed conflict and establish the international standards for humanitarian treatment.
Mr Justice Leggatt continued: “None of the claimants were engaged in terrorist activity or posed any threat to the security of Iraq.”
The court found that two claimants had been detained at sea and subjected to forced nudity and sexual humiliation. One of the claimants was burned on the buttock with a cigarette. The men were subjected to sleep deprivation and periods of complete deprivation of sight and hearing whilst in British custody.
The four men were awarded £84,000 in compensation.
The claims are being seen as test cases that may determine how a further 628 claims are dealt with by the Ministry of Defence (MoD).
In addition, 331 claims have been settled out of court, with the MoD paying out £22m as of the end of 2016.
They were brought at a time of sustained complaints in Westminster and in sections of the press that Iraqis bringing claims against British troops were essentially dishonest and represented by “ambulance-chasing” lawyers.
Sapna Malik, a partner at the London law firm Leigh Day, which represented the four men, said: “These trials took place against an onslaught of political, military and media slurs of Iraqis bringing spurious claims, and strident criticism of us, as lawyers, representing them.
“Yet we have just witnessed the rule of law in action. Our clients are grateful that the judge approached their claims without any preconception or presumption that allegations of misconduct by British soldiers are inherently unlikely to be true.
“Our clients’ evidence has been tested at length in court and the Ministry of Defence has been found wanting.”