Соответствующая норма
Practice Relating to Rule 124. ICRC Access to Persons Deprived of Their Liberty
Switzerland’s Basic Military Manual (1987) provides:
The Protecting Powers and the ICRC shall ensure respect for the international rules established in favour of prisoners of war to protect their interests. To this effect, they shall cooperate with the Detaining Power, which shall facilitate their tasks. The prisoners of war shall always have the ability to lodge complaints to the Protecting Power. 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 108.
Switzerland’s ABC of International Humanitarian Law (2009) states:
International Committee of the Red Cross (ICRC)
The role and duties of the ICRC in an Armed conflict are defined in the Geneva Conventions of 1949 and their Additional Protocols. The ICRC’s most important tasks include visiting prisoners, …
Prisoners of war
The conditions of detention, and use as a workforce, are regulated by the Third Geneva Convention. Prisoners of war have the right to be visited by delegates of the International Committee of the Red Cross (ICRC). 
Switzerland, Federal Department of Foreign Affairs, ABC of International Humanitarian Law, 2009, pp. 25 and 34.
[emphasis in original]
In 2011, in answer to an interpellation in Parliament, Switzerland’s Federal Council stated: “The representatives of the Federal Department of Foreign Affairs do not fail to regularly remind the de facto authorities in Gaza of their international obligations, notably as concerns the right of the ICRC to visit the Israeli soldier Gilad Shalit.” 
Switzerland, Answer by the Federal Council to interpellation 10.3991 in Parliament regarding the right of Gilad Shalit to receive visits from the ICRC, 16 February 2011.