(Cover) - EN Showbiz - Ryan Phillippe's ex-girlfriend has given birth to a baby girl.

Alexis Knapp reportedly welcomed daughter Kai alongside the actor, who was said to be at her side during the birth at Cedars-Sinai Medical Centre. There are still doubts as to whether Ryan is the father, following the couple's split last year. They had only been dating for a few months, with Alexis revealing she was pregnant after their breakup. However, he is prepared to take full responsibility if the child is his.

According to In Touch, Alexis gave birth on Friday, with an insider telling the publication that "it was a smooth delivery". Baby Kai weighed in at 8lbs.

"Ryan took Alexis to her last doctor's appointments and was there in the hospital when she gave birth," the source said. "He's waiting for the DNA test to see if he's the father, but he's acting like he is."

The movie hunk already has two kids with his ex-wife Reese Witherspoon, Ava, 11, and seven-year-old Deacon.

At the time Alexis' pregnancy was revealed, Ryan, 36, was dating Amanda Seyfried. They have since parted ways, but it's been claimed the romance was never that serious.

Alexis has starred in several films recently, including Couple's Retreat and the forthcoming Miley Cyrus film So Undercover. (C) Cover Media