Celebuzz.com reports:

" Nearly two months after an ugly Christmas incident during which Charlie Sheen was accused of attacking his wife Brooke Mueller with a knife, the Two and a Half Men actor has entered rehab as what his rep is calling a "a preventative measure." Mueller checked into a rehab facility in Malibu, California, earlier this month, reportedly to seek treatment for a crack-cocaine addiction, but switched facilities this week due to confidentiality concerns.

People.com reports:

"As a preventative measure, Charlie Sheen has entered a rehabilitation facility," his rep says in a statement. "He will take some time off his series Two and a Half Men."

The statement did not elaborate on the reason for Sheen's treatment. The actor has reportedly gone to rehab programs at least twice before for drug and alcohol abuse, but a source says that this time the problem relates to the fallout from the domestic violence case.