Tariq Aziz, the former deputy prime minister of Iraq, is due to stand trial for crimes against humanity.
The 72-year-old has not been seen in public since giving himself up to US troops two weeks after the fall of Baghdad in 2003.
Mr Aziz, a fluent English speaker born into a Chaldean Catholic family, became the face of Saddam Hussein’s government during the first Gulf war and the following years.
He is due in court in Baghdad’s heavily-fortified Green Zone to answer charges relating to the execution of 42 businessmen in 1992.
The traders were rounded up over two days in July before being executed hours later after being accused of raising food prices at a time when Iraq was struggling under United Nations sanctions.
Mr Aziz, whose co-defendants include condemned war criminal Ali Hassan al-Majid â€“ also known as Chemical Ali – faces death by hanging if convicted over the allegations.
But his layer Badia Arif has said there is “no credible accusation” against his client.
“The prosecution assumes that just because he was a member of the Revolutionary Command Council, which carried out the death sentences, he is guilty,” he told reporters.
The former deputy prime minister’s family meanwhile have claimed that Mr Aziz is being punished by the Iraqi authorities for refusing to testify against Saddam in the ex-president’s trial for genocide and crimes against humanity