Claims by Iraq's fugitive Sunni vice president that his bodyguard was tortured while in custody were denied on Thursday by authorities, who insisted he died of kidney failure.

Amir Sarbut Zaidan al-Batawi died earlier this month and his body was handed over to his family, with Vice President Tareq al-Hashemi, wanted by Baghdad on terror charges, releasing photographs he said showed the 33-year-old married father-of-three was tortured.

A senior Iraqi general and a judicial spokesman, however, said Batawi died of kidney failure and other conditions after refusing treatment.

"He died because he had a serious disease in his kidney, and he refused to be tested and to be treated," Lieutenant General Hassan al-Baydhani, chief of staff of Baghdad's security command centre, told AFP on Thursday.

Asked about Hashemi's claims of holding photographic evidence of Batawi suffering torture, Baydhani replied, "It is easy for Photoshop to show anything," referring to a popular digital photo editing software.

Higher Judicial Council spokesman Abdelsattar Birakdar added that Batawi was regularly examined by doctors at multiple Baghdad hospitals and in the prison where he was being held.

Birakdar said investigators filmed Batawi confessing to criminal activity on January 14, but declined to give specifics, and said he was involved in no further inquiries afterwards.

"The deceased's corpse was sent to the morgue for an autopsy to state the cause of death," he said in a statement. "The initial autopsy showed the cause of death to be extreme diarrhea, reduction in blood pressure, and kidney failure."

Hashemi released a statement on Wednesday in which he said Batawi had died and his body was handed to his family on March 18, around three months after his initial arrest.

"There were signs of torture in several parts of his body, including several sensitive places, a cause of savage methods used on him during the investigation," the statement said.

Birakdar said the body was transferred on March 20. It was unclear what was behind the discrepancy.

In December, shortly after US troops completed their withdrawal from Iraq, the country's Shiite-led authorities issued an arrest warrant for Hashemi, a Sunni, on terror charges, sparking a protracted political cr6isis.

Hashemi, who has remained in Iraq's autonomous Kurdistan region for the duration of the row, says the allegations are politically-motivated and Kurdish officials have refused to hand him over to the central government.