Actress Kellie Waymire, a familiar face on TV shows including Six Feet Under, Friends and Ally McBeal, has died from a previously-undetected medical condition, her agent says.

Waymire, 36, died on November 13 at her home in Los Angeles, said Billy Miller. He did not disclose what medical condition she had, saying final autopsy results were pending.

Although best known for several TV appearances, including a recurring role on Six Feet Under as Melissa the prostitute, Waymire also gained acclaim for her work in regional theatre.

The Los Angeles Times called her performance as the lead in AR Gurney's offbeat play Sylvia, at San Diego's Old Globe Theatre in 1996, "utterly irresistible". The role, which she performed in San Francisco as well, won her a Drama-Logue Award.

Waymire also appeared in a revival of Noel Coward's Present Laughter, at the Pasadena Playhouse, in 1998 and in many other stage productions across the US.

She began her television career on the soap opera One Life To Live, going on to appear on such shows as Seinfeld, The Practice, Judging Amy, Star Trek: Voyager, Star Trek: Enterprise, The X-Files NYPD Blue and CSI: Crime Scene Investigation.

The actress, originally from Columbus, Ohio, attended Southern Methodist University, where she won the Greer Garson Award. Later, she earned a master of fine arts degree from the University of California, San Diego