BEVERLY HILLS, Calif.  —  Angelina Jolie and Billy Bob Thornton have adopted a Cambodian boy, the actress' father, Jon Voight, told reporters.

"Angelina just got a baby yesterday. Angelina adopted a Cambodian baby. I'm a grandfather today," Voight said at Monday's Academy Awards luncheon at the Beverly Hilton Hotel. He's nominated for best supporting actor for his role as Howard Cosell in Ali.

The 26-year-old actress took custody of the baby on Sunday in Africa, where she is shooting a film. Thornton, 46, was in the United States.

"She's alone," Voight said. "I'd be happy to go to Africa and baby-sit, change diapers."

Voight said he didn't know whether the couple had picked a name for the child. Their publicist, Arnold Robinson, didn't immediately return telephone messages Tuesday seeking comment.

Jolie, who won a supporting-actress Oscar for Girl, Interrupted, and Thornton were married in Las Vegas in May 2000. Thornton stars with Academy Award nominee Halle Berry in Monster's Ball.