Oscar winner Jennifer Hudson's seven-year-old nephew was found dead in the back of an SUV yesterday, ending a frantic search that began after the shooting deaths of her mother and brother three days earlier.

The singer and actress was among seven family members and close friends who cried and held hands as they identified Julian King's body from a live image on a television screen at the Cook County Medical Examiner's office yesterday afternoon.

Chicago police spokeswoman Monique Bond said the boy, like his grandmother and uncle, had been shot. The medical examiner's office planned an autopsy today.

Chicago Police Superintendent Jody Weis said a motive remained unclear but added, "It wasn't a case of a stranger-type homicide."

Police have characterized the slayings as "domestic related" and authorities have been questioning the boy's estranged stepfather, who is being held in state custody on a parole violation. No one has been charged in the slayings.

Julian's body was found shortly after 7 a.m. in the rear seat of the SUV, which was parked on the street in a neighbourhood about 16 kilometres from the home he shared with the other victims. The vehicle matched the one mentioned in an Amber Alert issued for Julian.

Hudson, 27, had offered $100,000 Sunday for information leading to the safe return of her nephew, the son of her sister, Julia Hudson. Hudson's publicist did not immediately return calls and e-mail messages yesterday.

"Miss Hudson wanted to request privacy," a Cook County spokesperson said after the family left the medical examiner's office.

The Amber Alert had listed William Balfour, the estranged husband of Julia Hudson, as a suspect in a "double-homicide investigation." Weis said Monday that Balfour "remains a person of interest."

Balfour, 27, was taken into custody for questioning Friday after the bodies of Hudson's 57-year-old mother, Darnell Donerson, and 29-year-old brother, Jason Hudson, were found. On Sunday, Balfour was transferred to the Illinois Department of Corrections.

Corrections records show Balfour spent nearly seven years in prison for attempted murder, vehicular hijacking and possessing a stolen vehicle.

Balfour's mother, Michele Balfour, has said Hudson's mother kicked Balfour out of the family home last winter. She denied her son had anything to do with the killings.

Lynette Louden, 47, said she called police about the SUV across the street from her home on Chicago's West Side after her family's dog started barking at it early Monday. Some neighbours said they hadn't seen the vehicle before Monday, but Louden said it had been there since at least Saturday.

"I only hoped the body wasn't in there," she said. "When they said that it was, I cried."