Here's some advice: If you're harboring a missing $30 million Warhol in your home, try to take it off the wall before filming an interview for your new reality show. Failure to follow this simple maxim has led a private investigator searching for a Pop Farrah Fawcett portrait straight to actor Ryan O'Neal, the late actress's longtime partner. The missing Warhol silkscreen portrait can be seen hanging above O'Neal's bed in the first episode of "Ryan and Tatum: The O'Neals," a documentary series about the actor and his daughter on the OWN network.   

The investigator was hired by Fawcett's alma mater, the University of Texas, where she studied art. In her living trust, the "Charlie's Angels" star left her entire art collection to the university — but when the institution slowly began assembling Fawcett's holdings after her death two years ago, it was unable to track down one of the two portraits Warhol made of Fawcett in 1980. They are reportedly the most valuable works in her collection.

A passage in actress Tatum O'Neal's new memoir, "Found: A Daughter's Journey Home," initially tipped off the university to the portrait's whereabouts. O'Neal describes her father's home: "On every wall, there are pictures of us and the rest of the family in our golden days. The original poster from 'Paper Moon,' Andy Warhol's portrait of Farrah." Good one, Tatum.

"That was a 'Thank God, we've caught you' moment," Fawcett's friend and former business partner Craig Nevius, who is assisting in the search, said to ABC. "I told the university, 'Be patient and wait, because this man is so arrogant, he's going to show it.'" Fawcett left nothing in her will for O'Neal, her partner for 30 years.

Regardless of the fate of the second Warhol portrait, Fawcett has already been enshrined in another American art institution. Executors of her estate donated the red one-piece bathing suit she wore in her famous 1976 poster to the Smithsonian Museum of American History in February. It will go on temporary display later this year.

Last summer, an Warhol Polaroid of Fawcett — which also served as the basis for the silkscreen portraits — sold at Sotheby's landmark Polaroid Collection sale for $43,750.