The head of a United Nations body investigating crimes by the Islamic State group in Iraq expressed regret over "misunderstandings" that led to the premature end of its crucial mission, at Baghdad's request.
IS seized vast swathes of Iraq and neighbouring Syria and proclaimed a "caliphate" in 2014, carrying out abductions, beheadings, ethnic cleansing, mass killings and rapes.
UNITAD was set up in September 2017 -- as IS was being driven out of its last major strongholds in Iraq -- by the UN Security Council to investigate genocide and war crimes by the Sunni Muslim extremists.
In an interview with AFP, UNITAD head Ana Peyro Llopis reflected on its seven-year effort to bring the jihadists to justice, and said "misunderstandings" with the Baghdad authorities contributed to the mission's closure later this month.
Peyro Llopis noted it has been the only such international investigation mission to be established on the ground.
"There are not many who would have opened their doors to us in such a generous way" to investigate crimes, she said in the telephone interview.
"We could have publicly recognised, more clearly, that the good work we were able to do was only possible because we were invited and that it is unique."
UNITAD's mission will end on September 17, years ahead of its expected completion, after the Security Council last year renewed its mandate for only one year at the request of Iraq's government.
"The Iraqis have seen concrete results in foreign jurisdictions, and got the impression that UNITAD cooperated more with foreign states than with Iraq," said Peyro Llopis.
"Everything could have been better explained," she added.
A major bone of contention with Baghdad was the sharing of evidence.
"The United Nations has strict rules of confidentiality and respect for the consent of those who testify," she said, meaning that not all evidence was passed on to the Iraqis.
Media reports spoke of tensions between UNITAD and the Baghdad government.
There have been IS-related prosecutions elsewhere, mainly in Europe, that have involved UNITAD documents and have resulted in 15 convictions.
But at a UN Security Council meeting in December 2023 an Iraqi representative said Baghdad had not received any evidence from the mission that could be used in criminal proceedings.
Once UNITAD's mission in Iraq comes to an end, its work will not be over.
"We have information in New York that is accessible," Peyro Llopis said.
However, if a state wants access to this information, "we have no legal framework" to pass it on.
She said the issue has been before the Security Council since last January, admitting: "We have no answer. This is a political question."
During its mandate, UNITAD wrote 19 reports on IS, including on specific crimes against minority Shiites and Yazidis and on the structure of the group.
It amassed 40 terabytes of digitised documentation, greatly helped by the IS obsession for administrative archives.
"We also worked on excavating mass graves," Peyro Llopis said.
"We recovered remains from 68 graves holding around 1,000 victims, 200 of whom we were able to identify."
In March 2019, the last IS stronghold in Syria fell. The "caliphate" was no more, despite IS affiliates continuing to sow terror on several continents.
The wheels of justice are slow and imperfect, and many crimes have gone unpunished. There are still mass graves in Iraq, and there are still personal testimonies of IS brutality to be recorded.
Under UNITAD's mandate, it is "an independent and impartial investigative team" set up to promote accountability of IS members "for their international crimes amounting to war crimes, crimes against humanity and in some cases, genocide in Iraq".
The UN mission has in the past said one of its aims is fair trials.
Inside Iraq, the courts have handed down hundreds of death sentences or life terms in prison in cases involving suspected members of the jihadist group.
However, there has also been criticism from human rights organisations of trials conducted too swiftly, and of some confessions being obtained under torture.
