Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 92. Mutilation and Medical, Scientific or Biological Experiments
The UK Military Manual (1958) prohibits measures that cause physical suffering, including mutilations or scientific and medical experiments on protected persons. This rule also applies in occupied territories. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, §§ 42, 282 and 549.
The manual specifies that biological experiments and “wilfully causing great suffering or serious injury to body or to health” are grave breaches of the 1949 Geneva Conventions. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 625(a).
The UK LOAC Pamphlet (1981) provides that neither wounded and sick members of the opposing forces nor civilians may be subjected to biological experiments. 
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 6, p. 22, § 2 and Section 9, p. 35, § 9.
The UK LOAC Manual (2004) states in its chapter relating to the wounded and sick: “Violence and biological experiments are forbidden.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 7.3.
The manual further states:
7.5. “The physical or mental health and integrity of persons who are in the power of an adverse Party or who are interned, detained or otherwise deprived of liberty” as a result of armed conflict “shall not be endangered by any unjustified act or omission.” “Any medical procedure which is not indicated by the state of health of the person concerned and which is not consistent with generally accepted medical standards which would be applied under similar medical circumstances to persons who are nationals of the Party conducting the procedure and who are in no way deprived of liberty” is prohibited.
7.5.1. In dealing with medical treatment on the basis of real medical need on the part of the patient, the law repeats fundamental medical ethics. The aim is to prevent experiments or unjustified medical operations on persons who are in no position to give their free consent. This protection extends to all those in the hands of an enemy or other party and even to citizens of the detaining power who are interned for reasons related to the armed conflict. In the absence of real medical justification, all persons are protected from physical mutilations, medical or scientific experiments or removal of tissue or organs for transplantation even with their consent unless these acts are justified under the general principles outlined in paragraph 7.5.
7.5.2. The only exceptions to the express prohibitions mentioned above relate to the voluntary donation of blood for transfusions or skin for grafting. Such donations must be for “therapeutic purposes, under conditions consistent with generally accepted medical standards and controls designed for the benefit of both the donor and the recipient.” “Voluntary” means that the donor must be capable of expressing his complete agreement, without any coercion or inducement.
7.5.3. Medical records relating to all medical procedures should, if possible, be kept. These medical records must be available at all times for inspection by the protecting power.
Right to refuse consent
7.6. Persons protected under paragraph 7.5 have the right to refuse any surgical operation. In cases of refusal, medical personnel must try to obtain “a written statement to that effect, signed or acknowledged by the patient”. The right still exists to carry out surgery necessary to save life in an emergency without obtaining the consent of the patient in accordance with medical ethics and on the same basis as for the general population under domestic law. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, §§ 7.5–7.6; see also § 9.4.
[emphasis in original]
In its chapter on prisoners of war, the manual states:
8.29. In relation to prisoners of war the following acts and omissions by the detaining power are prohibited:
b. Physical mutilation or medical or scientific experiments, even with consent.
c. Any medical treatment, even with the consent of the prisoner of war, including removal of tissue or organs for transplantation, unless it is:
(1) necessitated by the health of the person concerned;
(2) consistent with generally accepted medical standards; and
(3) applied in similar circumstances to those which would apply to nationals of the detaining power.
An exception to this rule is that prisoners of war may consent to give blood for transfusion or skin for grafting provided that consent is given voluntarily and without any coercion or inducement, and then only for therapeutic purposes. Generally accepted medical standards must be applied together with controls designed for the benefit of both the donor and the recipient. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 8.29.
In its chapter on internal armed conflict, the manual restates the provisions of common Article 3 of the 1949 Geneva Conventions:
Under the terms of Common Article 3, the parties to a non-international armed conflict occurring in the territory of a party to the Conventions are obliged to apply “as a minimum”, the following provisions:
(1) Persons taking no active part in the hostilities, including members of armed forces who have laid down their arms and those placed hors de combat by sickness, wounds, detention, or any other cause, shall in all circumstances be treated humanely, without any adverse distinction founded on race, colour, religion or faith, sex, birth or wealth, or any other similar criteria.
To this end, the following acts are and shall remain prohibited at any time and in any place whatsoever with respect to the above-mentioned persons:
(a) violence to life and person, in particular murder of all kinds, mutilation, cruel treatment and torture. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 15.4.
In the same chapter, the manual prohibits
[the] “physical mutilation or … medical or scientific experiments of a kind which are neither justified by medical, dental or hospital treatment of the person concerned nor carried out in his or her interest, and which causes death to or seriously endangers the health of” [any person in the hands of a party to the conflict]. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 15.30.
In its chapter on enforcement of the law of armed conflict, the manual notes:
Additional Protocol I extends the definition of grave breaches to include the following:
a. any wilful act or omission which seriously endangers the physical or mental health or integrity of any person who is in the power of a party other than the one on which he depends and involves:
(1) subjecting that person to any medical procedure which is not indicated by the state of health of the person concerned and which is not consistent with generally accepted medical standards which would be applied under similar medical circumstances to persons who are nationals of the party conducting the procedure and who are in no way deprived of liberty;
(2) carrying out on such persons, even with their consent, physical mutilations, medical or scientific experiments, or removal of tissue or organs for transplantation, except where these acts are justified in conformity with the conditions provided for in (1) above, or, in the case only of donations of blood for transfusion or of skin for grafting, that they are given voluntarily and without any coercion or inducement, and then only for therapeutic purposes, under conditions consistent with generally accepted medical standards and controls designed for the benefit of both the donor and the recipient. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 16.25.
The UK Geneva Conventions Act (1957), as amended in 1995, punishes “any person, whatever his nationality, who, whether in or outside the United Kingdom, commits, or aids, abets or procures the commission by any other person of, a grave breach of any of the [1949 Geneva] conventions or of [the 1977 Additional Protocol I]”. 
United Kingdom, Geneva Conventions Act, 1957, as amended in 1995, Section 1(1).
Under the UK ICC Act (2001), it is a punishable offence to commit a war crime as defined in Article 8(2)(b)(x) and (e)(xi) of the 1998 ICC Statute. 
United Kingdom, ICC Act, 2001, Sections 50(1) and 51(1) (England and Wales) and Section 58(1) (Northern Ireland).
The UK Government Strategy on the Protection of Civilians in Armed Conflict (2010) states: “IHL requires parties to a conflict to respect and protect civilians. … [C]ivilians must not be … subjected to acts of violence such as … maiming”. 
United Kingdom, Foreign and Commonwealth Office, Government Strategy on the Protection of Civilians in Armed Conflict, March 2010, p. 4.
In 2010, in its closing submissions to the public inquiry into the circumstances surrounding the death of Baha Mousa and the treatment of those detained with him by UK armed forces in Iraq in 2003, the UK Ministry of Defence stated regarding common Article 3 of the 1949 Geneva Conventions: “On its face this protection is restricted to armed conflicts not of an international character. However, it is understood to apply in all forms of armed conflict as part of customary international law to set out the irreducible minimum standard.”  
United Kingdom, Ministry of Defence, Closing Submissions to the Baha Mousa Public Inquiry on Modules 1–3, 25 June 2010, § 10.2, p. 10.