Tsoni was found dead at her Athens apartment on Monday after calling the police, according to Greek newspaper Espresso. Her cause of death has not yet been confirmed.
Tsoni played the younger daughter in Lanthimos’ cinematic black comedy Dogtooth, which examined the bizarre brainwashing rituals of a family and was nominated for the 2011 Best Foreign Language Oscar and premiered at the 2009 Cannes Film Festival. Tsono and her co-star Angeliki Papoulia picked up the best actress prize for their roles in the Sarajevo Film Festival.
She also stared in 2010 drama Artherapy, 2009 comedy Evil in the Time of Heroes and, most recently, The Fruit Trees of Athens. Before becoming an actress, Tsoni was a singer in the punk band Mary and the Boy.