The chairman of a United Nations commission investigating possible war crimes in Syria has met that country’s ambassador only once, he said. It happened during a chance encounter in a hallway after he had given a briefing to the General Assembly in New York.
“Then for 15 minutes, he gave me a lecture,” the commission chairman, Paulo Sérgio Pinheiro, said of his exchange with the Syrian envoy, Bashar al-Jaafari. “We don’t have any hope that the Syrians will cooperate with us.”
Members of the commission, created by the United Nations Human Rights Council in August 2011, have never been permitted to visit Syria by the government of President Bashar al-Assad, which appears to view them as accomplices of Mr. Assad’s enemies.
The commission, with a support staff of about 25 people, has collected an enormous volume of material, which could be used in courts, about the atrocities committed in the six-year-old civil war by both Mr. Assad’s side and the groups arrayed against him.
The Syrian Mission to the United Nations did not respond to emails requesting comment.
The material collected from outside the country includes testimony from more than 1,400 witnesses and victims. The commission also reviews and corroborates photographs, video, satellite imagery, and forensic and medical reports from governments and nongovernmental sources to determine if there are “reasonable grounds to believe” an atrocity has been committed, according to its website.
“The fact that we don’t have access to Syria doesn’t mean that we don’t have access to information inside Syria,” Mr. Pinheiro said last week in an interview that included some of the commission’s workers.
And, he said, the commission’s work carries more credibility than evidence of war crimes in Syria compiled by other groups because its work is not financed by one side or the other.
“A lot of organizations are documenting the war crimes, they are serious and committed people, but of course they are funded by states that have a vested interest,” Mr. Pinheiro said. “At least we are being funded by the regular budget of the United Nations.”
Besides Mr. Pinheiro, a Brazilian political scientist, his fellow commissioners are Karen AbuZayd of the United States, a longtime United Nations diplomat, and Carla Del Ponte of Switzerland, a former war-crimes prosecutor. They are also responsible for compiling a list of suspected perpetrators of war crimes in Syria, which is kept in a sealed envelope in the custody of the Office of the High Commissioner for Human Rights, Zeid Ra’ad al Hussein. Even Mr. Hussein has not seen the list, Mr. Pinheiro said.
Ravi Kumar Reddy, the legal adviser for the Syria commission, said the list was updated annually and would remain secret.
Mr. Reddy would not disclose how many people were on the list, saying “it would be unwise.” But Mrs. AbuZayd said: “Not as many as you’d like to think.”
Commission members were in New York last week to meet with the United Nations secretary general, António Guterres, and to speak about some of their findings at an informal Security Council session.
Mr. Pinheiro and his aides told them that increasing numbers of civilians were now concentrated in northern Syria, where much of the fighting was among militants whose alliances kept shifting.
“New conflicts are emerging in which civilians are caught up between all these actors,” said Anis Anani, the commission’s political adviser. While the Islamic State militants are losing territory in northern Syria, he said, “it’s also giving way to unstable dynamics on the ground.”
Whether the commission’s evidence will lead to an independent prosecution of suspected war crimes is unclear, even if the documentation is overwhelming. There is no clear path to make that happen.
The International Criminal Court, which was created for such a purpose, cannot open a case on Syria without a referral from the Security Council, where Russia — Syria’s ally — would almost certainly block it.
“The prospect of an I.C.C. referral is zero,” Mr. Pinheiro said.
But Mr. Reddy said the commission had supplied some information to judicial authorities in approximately 10 countries where legal cases related to the Syrian war were underway.
He declined to identify the countries or any of the cases.
Mr. Pinheiro’s commission also received a new source of support last December, when the United Nations General Assembly voted to create a separate panel to help lay the groundwork for possible prosecutions of Syria war crimes. The panel will “closely cooperate” with Mr. Pinheiro’s commission, the General Assembly’s resolution said.
Mr. Pinheiro said that when he agreed to lead the effort in 2011, he believed it would last a year.
The commission is already the longest-serving inquiry at the United Nations.
“The war is not winding down,” he said.