Michelle Trachtenberg's cause of death was ruled "undetermined" by the Office of Chief Medical Examiner in New York City, Fox News Digital confirmed.

The "Gossip Girl" and "Buffy the Vampire Slayer" actress was found unconscious and unresponsive in her New York City apartment.

Michelle Trachtenberg, who has died of as yet undisclosed causes aged 39, was an actress who found fame in Buffy the Vampire Slayer and Gossip Girl, two television series that foregrounded female power and agency;