Fisher found Stevens dead Feb. 26. An autopsy failed to immediately determine the cause of death. Foul play was not suspected, David Campbell of the Los Angeles County Coroner's Office said Friday.
During last year's presidential race, Stevens served as co-chairman of the Bush/Cheney Entertainment Task Force (search) and managed the campaign's relationships with entertainment industry leaders and film, television and music celebrities.
Stevens, an associate with the Washington lobbying group Barber Griffith & Rogers (search), specialized in foreign campaign consulting and advised candidates in 24 international elections, according to his biography posted on the firm's Web site.
Fisher played Princess Leia in the "Star Wars" trilogy and is the author of several books, including "Postcards From the Edge."
Her publicist said Friday the actress is "distressed" and waiting to learn the cause of Stevens' death.
"He's one of her best friends," publicist Carol Marshall said. "He was staying at her house as many of her friends do when they come into town."