U.S. actor Charlie Sheen has relinquished legal custody of Sam and Lola, his daughters with his ex-wife, actress Denise Richards, a source told E! News.

The "Two and a Half Men" star reportedly agreed about a month ago to give up the joint custody he and Richards shared of the girls.

The news comes as Sheen and his current wife, Brooke Mueller, have sought treatment for substance abuse. Sheen was also arrested in December after Mueller, the mother of his twin toddler-age sons, claimed he assaulted and threatened her. Sheen has pleaded innocent to the charges, and the couple has said they are working on their marriage.

Richards "was just too nervous leaving the kids with Charlie or letting them go to his house," an insider told E! News. "She told him if he did (fight her over the custody) she was going to have to take him to court."