A source told People that the actor and the Russian singer, who welcomed a daughter together – Lucia – back in October 2009, "just drifted apart."
"They're both working hard on their careers and trying to raise a sweet baby together," the source close to the pair added. "They're still friends and they'll both raise Lucia together."
Among their work obligations are a new film for Mel – "How I Spent My Summer Vacation," which is currently shooting in Mexico — and music writing for Oksana, the mag reported.
The split will no doubt come as a surprise to fans of the star, as Mel was gushing about both mom and his new daughter in an interview with Access Hollywood's Shaun Robinson in January.
"She luckily looks more like her mother than me and is an angel and the mother, turns out she's a wonderful mother," Mel told Shaun.
Mel even opened up about why the two weren't heading down the aisle.
"She'd make anyone a wonderful wife, but for the moment, she's a mother," he said.
A Gibson rep had no comment to the mag.
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