Police in Chicago have made an arrest in the murder inquiry surrounding the deaths of actress Jennifer Hudson's mother and brother.

They had been looking for 27-year-old William Balfour, considered armed and dangerous, but had refused to say what connection he had to the Hollywood star's family.

All they would say is that the shootings may have arisen from a domestic disturbance.

E Online Video - More article below

Hudson's mother, 57-year-old Darnell Donnerson, and her brother, 29-year-old Jason Hudson were murdered in their home on Chicago's South Side.

Seven-year-old Julian King, Hudson's mother's grandson, was thought to have been abducted by Balfour, who was released from prison two years ago.

Police said neighbours reported hearing shots in the area during the morning but the bodies were not found until mid-afternoon.

Hudson gained notice as a contestant on No. 1-rated US television talent show American Idol during its third season in 2005. She was one of 12 finalists but was voted off.

Still, her booming voice and popularity kept her touring in live shows and eventually she earned the role as Effie White in the 2006 film version of stage musical Dreamgirls.

The role of soulful singer White, who is kicked out of an all-girl 1960s singing group, earned Hudson the Oscar for best supporting actress and made her an instant star in Hollywood.

Since then Hudson has appeared in the movie version of Sex and the City, and is currently in The Secret Life of Bees.

Media reports said Hudson was in Florida when she was told of the shootings and was headed back to Chicago.