Hollywood heartthrob and Oscar-winning actress Julia Roberts is pregnant with twins, according to reports.

The Pretty Woman star is due to give birth early next year, People magazine quoted Roberts' spokeswoman, Marcy Engelman, as saying on Monday.

US Weekly said Roberts, 36, has been pregnant for about nine weeks.

The twins are a boy and a girl, Star magazine quoted sources as saying.

Roberts married cinematographer Daniel Moder, 35, in July 2002 at her home in New Mexico.