GENEVA (Reuters) - International investigators are moving ever closer to finding justice for victims of atrocities in Syria’s eight-year war that has killed hundreds of thousands of people, the head of a U.N. war crimes body said.

Catherine Marchi-Uhel of France, head of the International, Impartial and Independent Mechanism (IIIM) attends an interview with Reuters at the United Nations in Geneva, Switzerland, March 7, 2019. REUTERS/Denis Balibouse

Former French judge Catherine Marchi-Uhel told Reuters her office had received 15 requests from national judicial or prosecution authorities for cooperation on Syria-related cases in five countries, and amassed a million records in all.

“We are progressing I have no doubt, we are going in the right direction,” said Marchi-Uhel, who heads the International, Impartial and Independent Mechanism set up in 2016 to probe and help prosecute the most serious crimes committed in Syria.

During the war, large numbers have died in air strikes and bombardment of city streets, the United Nations has documented repeated chemical weapons attacks on civilians, and countless have faced torture, summary execution and disappearance.

“We are already going in that direction of identifying the most serious crimes, identifying perpetrators, not just physical perpetrators but those who orchestrated, assisted or condoned the commission of crimes that are really our mandate,” Marchi-Uhel added at the interview in her Geneva office.

“Does it give a prospect of justice a better chance? Yes”.

In a boost to the hunt for justice, police last month detained two Syrians in Germany and one in France on suspicion of torturing opposition activists and other crimes against humanity. They were the first such arrests in Europe against suspected figures from the feared security service.

JORDAN AND SWEDEN CASES

Marchi-Uhel, who used to work for the International Tribunal for the former Yugoslavia, declined to say which countries she was working with. But she said her 32 staff had gathered one million documents, videos and witness testimonies - equal to four terabytes - which were being analyzed by investigators, lawyers, and “e-discovery officers”.

She is building on evidence gathered by the separate U.N. Commission of Inquiry on Syria, a body of independent experts headed by Brazilian Paulo Pinheiro since 2011.

“My mandate is to investigate the most serious crimes from all sides and do preparatory work for those most responsible for those crimes to face justice,” she said.

“I don’t sign off on any indictment. With the team we have stopped when we consider a case is ready (for prosecution) ... These things take a long time. It is not a bad sign, it means authorities are working seriously.”

Efforts to prosecute members of President Bashar al-Assad’s government have repeatedly failed, as Syria is not a signatory to the Rome Statute of the International Criminal Court (ICC) in The Hague. Russia and China have also vetoed attempts to give the ICC a mandate to set up a special tribunal for Syria.

“The avenue that exists at the moment are national jurisdictions,” Marchi-Uhel said.

However, lawyers representing 28 Syrian refugees in Jordan this week asked the ICC to investigate Syria, arguing the court has jurisdiction because Jordan is a signatory.

Also, nine torture survivors submitted a criminal complaint in Sweden on Feb 19 against Syrian officials, invoking universal jurisdiction, Marchi-Uhel noted.