A brother-in-law of the judge trying Saddam Hussein for genocide was shot dead by gunmen while driving in western Baghdad.
A police source said that the ten-year-old nephew of chief judge Mohammed al-Ureybi and a third person in the car were wounded in the attack yesterday evening.
A second source said the nephew had died and the third person, who was Mr Ureybi's sister, was seriously wounded.
It was not immediately clear if the attack was linked to Mr Ureybi's work at the Iraqi High Tribunal. He was appointed chief judge only last week after the government sacked his predecessor for telling Saddam the former president was "not a dictator".
Three defence lawyers working for Saddam and his co-accused have been killed over the past year, and international legal rights groups have questioned whether he can have a fair trial in a country on the brink of sectarian civil war.
Last night's gun attack took place in a largely Sunni neighbourhood. Mr Ureybi is from the majority Shia community. He has taken a firm line with the accused in the month-old trial for genocide against the Kurds and has ejected Saddam from court in each of the three sessions over which he has presided.
Tribunal judges, like leading Iraqi politicians, live under tight security. Militants have frequently targeted the relatives of prominent figures, seeking easier targets because the family members have far less - if any - protection.