Saddam Hussein objected on Tuesday to allowing a leading American forensic scientist to testify about his investigation into a mass grave of Kurds in the genocide trial of the former Iraqi leader.

Clyde Snow — an expert from the University of Oklahoma who has also investigated mass graves in Argentina, Guatemala and the former Yugoslavia — took the stand and began to give background on his work, but defense lawyers quickly argued that experts should be brought in to verify Snow's credentials.

Saddam insisted that Snow should not be allowed to testify because he was American and demanded neutral international experts, suggesting that the bodies in the grave may have been moved to the location from separate locations.

"No one should imagine I'm trying to defend Saddam Hussein, given the earlier sentence against me. You can only be executed once, not 10 times," he said, referring to the death sentence issued against him on Nov. 5 in an earlier trial on charges of killing Shiites. "I'm only trying to defend the truth."

Referring to the 2003 U.S.-led invasion that toppled his regime, Saddam proposed that "international experts be brought brought from countries which are not part of the aggression ... to determine the truth about the mass grave ... whether (the bodies) have been moved in from outside the area."

"Iraq is full of skeletal remains during the past centuries. Just give me 10 days and I'll show you a grave with 400 bodies, Arabs and Kurds. "The important thing is who is responsible ... Anything can be moved from place to place."

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Saddam and his co-defendants have pleaded innocent to charges of war crimes and crimes against humanity arising from their role in a military crackdown on Iraq's Kurd population in 1987-88. The prosecution says that about 180,000 people, mostly civilians, were killed in the campaign against the Kurds, which was code named Operation Anfal.

The chief judge dismissed the complaints, and Snow gave his testimony on the mass grave he investigated in 1992 in the northern Iraqi town of Koreme, as part of a team organized by the groups Physicians for Human Rights and Middle East Rights Watch.

Koreme was destroyed in August 1988, one of "3,800 villages that were destroyed during the Anfal campaign," he said. "We didn't have the resources to investigate all of these cases but we think Koremi was typical of what happened in all these villages."

Snow said that he was told by survivors that Iraqi forces detained the village's population — about 300 people — and separated out 33 men and boys, who were taken to a location nearby. There, the troops opened fire on them, killing 27, Snow said. The rest of the population was forced to leave the village, he said.

Snow showed a slide presentation of the 27 bodies his team exumed in two graves dug next to each other outside the village. Photos showed skeletons laying in the earth, still in their clothes, some with prayer beads or traditional Kurdish belts around them.

"I saw the bones were in excellent condition after four years, there was clothing and some of the bones had wounds consistent with gunshot wounds," Snow said. In one photo, he pointed out the copper fragment of a shell casing still embedded in a bone.

He detailed 84 gunshot wounds in the bodies, most of them to the head or upper body.

Snow was the first expert to testify in the Anfal trial, which began on Aug. 21 and until now has been hearing testimony from survivors of the campaign, who told of poison gas attacks on their villages and relatives taken away and killed.

Saddam and his co-defendants, all former officials in his regime, face possible death sentences if convicted on charges of crimes against humanity and war crimes.

Saddam and his cousin, Ali Hassan al-Majid — known as "Chemical Ali" because of his alleged use of chemical weapons during the Anfal campaign — also face charges of genocide in the case. The defendants have pleaded innocent to the charges.