A/HRC/30/61 J. Denial of humanitarian assistance 51. The investigation team found that the Government of Sri Lanka placed considerable restrictions on freedom of movement of humanitarian personnel and on humanitarian activities in the Vanni. These restrictions had an impact on the ability of humanitarian organizations and personnel to exercise their functions effectively and to ensure access to relief of civilians in need. According to rule 56 of customary international humanitarian law, such restrictions may only be justified by imperative military necessity. 52. There are reasonable grounds to believe that LTTE also failed to respect its obligations to respect and protect humanitarian relief personnel and not to restrict their freedom of movement. 53. The team found reasonable grounds to believe that the Government knew or had reasons to know the real humanitarian needs of the civilian populations in the concerned areas, including from its own agents on the ground, and nonetheless imposed severe restrictions on the passage of relief and the freedom of movement of humanitarian personnel. This conduct apparently deprived the civilian population in the Vanni of basic foodstuffs and medical supplies essential to survival. If established by a court of law, these acts and omissions point to violations of international humanitarian law, which, depending on the circumstances, may amount to the use of starvation of the civilian population as a method of warfare, which is prohibited by rule 53 of customary international humanitarian law. Such conduct, if proven in a court of law and depending on the circumstances, may constitute a war crime. K. Screening and deprivation of liberty of internally displaced persons 54. The investigation team believes that the internally displaced persons held in Manik Farm and other closed camps were deprived of their liberty for periods far beyond what would have been permissible under international law. Moreover, the material conditions in these closed camps amounted to violations of the rights to health and to an adequate standard of living, including food, water, housing and sanitation. Depending on the circumstances, such conditions may also amount to inhumane and degrading treatment as defined in international human rights law. 55. On the basis of the information in the possession of the team, there are reasonable grounds to believe that internally displaced persons IDPs were treated as suspects and detained because of their Tamil ethnicity and because they had come from territory controlled by LTTE. This conduct may amount to discrimination under international human rights law and, if established by a court of law, may amount to the crime against humanity of persecution. V. Steps towards accountability and reconciliation 56. As demonstrated in previous reports submitted by OHCHR to the Human Rights Council, recent years have witnessed a total failure of domestic mechanisms credibly to investigate, establish the truth, ensure accountability and provide redress to victims of the serious human rights violations and abuses described above. 57. In the course of its investigation, the team obtained access to the unpublished reports of several domestic investigations, including the Udalagama Commission of 2006 and the Army Court of Inquiry of 2012. The reports confirmed the concerns of OHCHR with regard 11