Tsoni in Dogtooth. (Photo: Kino Lorber)

Mary Tsoni, the Greek musician who starred as one of the unnamed siblings in director Yorgos Lanthimos’ acclaimed breakthrough film, Dogtooth, has died. The tabloid Espresso reports that Tsoni was found unconscious on Monday in her apartment in downtown Athens after calling for an ambulance. The cause of death remains undetermined. Tsoni was 30.

Born in Athens, Tsoni studied dance in London before pursuing a career in music as one half of a duo called Mary And The Boy. Though the surreal Dogtooth—one of The A.V. Club’s favorite movies of the past decade—wasn’t her first film role, it brought her to international attention. Tsoni played the youngest daughter of a factory owner who has raised his children to adulthood with no knowledge of the outside world, and she ended up sharing the Best Actress award at the Sarajevo Film Festival with Angeliki Papoulia, who played the role of her older sister and would go on to appear in Lanthimos’ subsequent films Alps and The Lobster.

With her jet-black hair and punk-goth style, Tsoni cut a figure on the festival red carpet that was impressively different from the childlike, awkward character she played in the film. (Furthermore, few who have seen the film’s cringe-inducing recital scene would presume that she had a background as a dancer or a musician.) Though she would go on to appear in a few more films—most notably the horror-comedy Evil: In The Time Of Heroes—Tsoni ultimately opted to focus on her music career. Mary And The Boy’s most recent album, Praying For Your Sins, was released in 2012. Tsoni was also a member of the art-rock band Joalz, whose next full-length, Amazing Moments, is due to be released in October of this year.