France, which is hosting the closed-door meeting, said the photos are part of a collection of 55,000 digital images of Syrians who were tortured and killed by president Bashar al-Assad’s regime.
The bodies of the emaciated young men in the photographs offer mute testimony to the savagery of a Syrian civil war in which more than 150,000 have died.
Starvation was only one form of torture they endured. Some bear the marks of strangulation and others have vivid bruises and welts from being beaten.
France said a majority of the images were collected by a Syrian military police photographer code-named “Caesar”, who smuggled them out on flash drives when he defected.
Syria’s justice ministry has dismissed the photos and accompanying report as “politicised and lacking objectiveness and professionalism” and a “gathering of images of unidentified people, some of whom have turned out to be foreigners”.
The ministry said some of the people were militants killed in battle and others were killed by militant groups.
The presentation at the Security Council is part of a process of documenting evidence of Syrian war crimes in the hope of eventually referring the perpetrators to the International Criminal Court (ICC) in The Hague.
That is unlikely to happen soon. Because Syria never accepted the jurisdiction of the ICC, the only way a case can be opened while Mr Assad is in power is for the Security Council to order a referral.
Russia and China have used their veto power three times to block resolutions threatening sanctions on Syria. The hope is that they will eventually agree to an ICC referral if a resolution names both Syrian government officials and rebels as war crimes perpetrators, according to a Western diplomat.
UN human rights chief Navi Pillay has been pushing the council to refer Syria to the ICC for three years, but Security Council president Joy Ogwu said last week there is no consensus for such a step.
However, France’s UN mission said the meeting “will also allow a discussion on the means to ensure accountability for these crimes”.
Ms Pillay said last week abuses by the Syrian government and rebels should be documented and brought to the international court.
But she added: “You cannot compare the two. Clearly, the actions of the forces of the government… killings, cruelty, persons in detention, disappearances, far outweigh those by the opposition.”
Ten of the photos were publicly released in January in a study known as the Caesar Report, which was funded by the government of Qatar, one of the countries most deeply involved in the Syrian conflict and a major backer of the opposition. More will be seen by the council.
Two of the authors of the Caesar Report will brief the council – David M Crane, who was first chief prosecutor of the Special Court for Sierra Leone, and Stuart J Hamilton, a forensic pathologist from the UK.
“Caesar” had been a crime scene photographer for the Syrian military, the report says. When the civil war began, he and his colleagues were reassigned to photograph the tortured bodies of rebels, providing proof to the regime that its enemies had been liquidated.
A relative of “Caesar” who defected early in the civil war kept in contact with him, and persuaded him to collect the images over the next three years, the report says.
The report’s authors found “Caesar” to be credible when they debriefed him in January, they wrote. “Caesar” smuggled out almost 27,000 images, the report said. The others came from similar sources.