The Hollywood Mystery of the Week appears to have been solved.

According to TMZ, Charlie Sheen will appear Tuesday morning on the "Today" show to admit that he's HIV positive. The announcement would come on the heels of wide-spread reports in recent days that a major entertainer contracted the virus several years ago and has spread it to several female companions.

The "Today" show interview with Matt Lauer would be a pre-emptive move to beat a National Enquirer story, scheduled to be released later this week after an 18-month investigation.

Sheen, once TV's highest-paid actor, has watched his career spiral in recent years after making anti-Semitic remarks about his "Two and a Half Men" boss, Chuck Lorre, and openly flaunting relationships with adult-film stars.

Access Hollywood is reporting that former wife Denise Richards has known about the disease for several years.