Actor Mel Gibson and his Russian-born singer partner were reported on Wednesday to have split up five months after the birth of their baby daughter. Celebrity websites People.com and UsWeekly.com, among others, cited unnamed sources as saying the “Braveheart” actor, 54, and Oksana Grigorieva, 39, had gone their separate ways some weeks ago. Gibson's spokesman declined to comment on the reports. The Oscar-winning actor and director went public about his romance with Grigorieva shortly after filing for divorce in April 2009 from his wife of nearly 30 years, Robyn. People.com said the pair “just drifted apart” and quoted an unnamed friend as saying the split was amicable and that they hoped to raise their baby, Lucia, together. Grigorieva, a classical pianist and model, released a debut pop music album in August. Gibson directed the music videos for four of the songs.