Jennifer Hudson is being sought for questioning ahead of the trial into the murders of three of her family members.

The Oscar winner's mother, brother and nephew were killed in October 2008 in a brutal triple homicide.

Her estranged brother-in-law William Balfour will stand trial in April accused of the killings.

The Chicago Sun-Times newspaper reports that defence attorney Amy Thompson is seeking out the singer to speak to her before the trial starts.

The legal team apparently wants to speak to Jennifer face to face in case she is called to the stand during the trial.

Although Jennifer has never been identified as a witness in the case, the lawyer reportedly wants to speak to the Dreamgirls star about text messages that were exchanged between herself and her mother Darnell Hudson Donerson, 57, around the time of the shooting.

Jennifer's brother Jason Hudson, 29, and seven-year-old nephew Julian King were also killed.

A Chicago police officer revealed at a hearing yesterday that during the course of their investigation, someone told officials that William had threatened to kill everyone in the home a couple of weeks before the murders.

However, William's defence attorneys claim that police did not have enough "probable cause" to arrest their client and have tried to have evidence from the murder scene thrown out.

The trial is expected to last up to three weeks. Jury selection will commence on April 9 with testimony starting on April 23.