X17 was the first to report back on December 29th that philandering husband slash golfer Tiger Woods checked into sex rehab at Arizona facility The Meadows...

Now, New York Times Magazine writer Benoit Denizet-Lewis - who has struggled with sex addiction himself - claims on his personal blog that Tiger is now at the Pine Grove/Gentle Path sex addiction treatment center in Hattiesburg, Mississippi. Denizet-Lewis says that various news sources have also confirmed this.

The writer also admits that Tiger likely "began his treatment at The Meadows in Arizona, but then left."

Apparently, the same thing happened to David Duchovny, says Denizet-Lewis! That the actor started off at The Meadows but, after becoming concerned that his privacy wasn't being protected, moved to a less high-profile sex rehab treatment center.

Think Tiger is serious about saving his marriage? At the Mississippi rehab, a patient must sign a "celibacy contract," meaning you can't have sex with anyone OR masturbate while in treatment.

Damn!