ABC News' Maria Nikias and Alison Kenworthy report:

Farrah Fawcett's longtime love actor Ryan O'Neal and the University of Texas at Austin are locked in a custody battle over a portrait of the late actress-and it's not just any old painting. The likeness was painted by artist Andy Warhol, and each side is claiming they are the rightful owner.

A trial between O'Neal and the college opened Monday in Los Angeles over the painting done by Warhol in 1980.

In her will, Fawcett bequeathed "artwork and any objects of art … to the University of Texas," which argues that both portraits belonged to Fawcett, and thus to the university.

"It's what Farrah wanted," David Beck, the lawyer of University of Texas at Austin, said. "She said all. And at least in Texas, all means all."

However, O'Neal claims the painting was given to him by Warhol, hung in his home for years and was only being stored by Fawcett during a break in their on-again, off-again relationship. The painting was spotted hanging back in O'Neal's home when it aired on his reality show, "Ryan and Tatum: The O'Neals," and O'Neal maintains he wants the piece for sentimental value.

"If it was a soup can from Andy Warhol, we wouldn't be here today," Marty Singer, O'Neal's lawyer, said. "It's his lover; the person he spent most of his life with."