Naomi Watts, Liev Schreiber Welcome Baby Boy

The Aussie actress' rep confirms to E! News that Watts gave birth to the couple's second child on Dec. 13

And baby makes four.

Naomi Watts and Liev Schreiber welcomed their second child Saturday, son Samuel Kai Schreiber.

Their new addition weighed 7 pounds, 13 ounces upon arrival.

"Both mom and baby are doing great," Watt's publicist, Robin Baum, said in a statement today.

The new details come a day after the rep for Watts, 40, exclusively confirmed the birth to E! News.

The happily unmarried couple have been together since 2005. Their first son, Alexander Pete, was born July 25, 2007, in Los Angeles.

(Originally published Dec. 14, 2008 at 10:00 a.m. PT)