Known as the Mukhabarat, the intelligence organisation was believed to have tortured and murdered thousands of opponents of the regime.

The Baath party official was taken into custody by US forces in April 2003. At the time, he was described as a presidential adviser with in-depth knowledge of the inner workings of Saddam Hussein's regime.

Barzan was a leading figure in the Mukhabarat from the 1970s, later taking over as director. A US official, speaking on the condition of anonymity at the time of his capture, said that during his time in the secret police, Barzan had played a key role in the Iraqi regime's execution of opponents at home and assassinations abroad.

The US official said that Barzan was also known for his ruthlessness and brutality in purging the Iraqi military of anyone seen as disloyal.

Targeted

Barzan became Iraq's representative to the United Nations in Geneva - including the UN human rights committee - in 1989. He was in Geneva for almost a decade, during which he is believed to have managed clandestine accounts for the Iraqi president's overseas fortune.

Barzan was among the leadership figures that US forces targeted during the war. In April 2003, warplanes dropped six satellite-guided bombs on a building in the city of Ramadi, west of Baghdad, where he was thought to be.

Despite falling out of favour with Saddam Hussein at one time, he was believed to have been a presidential adviser at the time of his capture.

Awad Hamad al-Bander

The man expected to be hanged with Barzan, Awad Hamad al-Bander, was chief justice of the Iraqi Revolutionary Court. According to his indictment, he conducted show trials which often lead to summary death sentences.

He was the head of the Revolutionary Court which issued death sentences against 143 Dujail residents, in the aftermath of the failed assassination attempt on the president on July 8, 1982.