Isis is harvesting human organs and murdering doctors who refuse to take part in the practice, according to Iraq's ambassador to the UN.
Mohammed Alhakim called on the 15-member UN Security Council to investigate evidence that Isis is removing organs from captives, after bodies with surgical incisions and missing organs were discovered in mass graves.
"We have bodies. Come and examine them," he said. "It is clear they are missing certain parts," Alhakim said.
"It is clear they are missing certain parts," he said, and claimed there were reports Isis militants had murdered doctors in northern Iraq who had refused to remove organs.
"These terrorist groups have desecrated all human values. They have committed the most heinous criminal terrorist acts against the Iraqi people whether Shi'ite, Sunni, Christians, Turkmen, Shabak or Yazidis," Alhakim told the Security Council.
The UN's envoy to Iraq, Nikolai Mladenov, backed Alhakim's claims, and said that there is testimony to support claims that Isis was harvesting organs to fund its cause.
He said in January alone, 790 people had been killed in the fighting between the jihadist group and government forces.
Mladenov said Iraq's most important goal was to win back the territory Isis seized in Iraq last year, including the country's second biggest city, Mosul.
He added that there are reports of atrocities committed by Shia militias after areas formerly under Isis control had been retaken.
"Especially worrying is the increasing number of reports of revenge attacks committed particularly against members of the Sunni community in areas liberated from ISIL control," Mladenov said.
Last December, Al Monitor spoke to a doctor in Mosul who claimed that foreign and Arab surgeons were hired to work in a local hospital and forbidden to speak to local doctors.
Information was leaked that they were removing organs from fallen fighters, injured people who were abandoned, and people who were kidnapped.
The organs were then transported through networks specialising in trafficking human organs.