American actors Jennifer Garner and Ben Affleck are expecting a second child, celebrity weekly People has reported on its website.

Citing an unnamed source, People said the former heroine of the television series Alias is four months pregnant. Contacted by AFP, the 36-year-old actress's spokeswoman had no comment.

Garner, a co-star in the 2007 hit Juno, and Affleck were married in June 2005. Their daughter, Violet, was born in late 2005.

Affleck, 35, who wrote the screenplay for last year's thriller Gone Baby Gone, co-starred with Garner in the films Daredevil and Pearl Harbor.

He shared an Oscar for best screenplay with his friend Matt Damon in 1997 for Good Will Hunting.