Serhat Mustafa Kilic, a well-known actor who played the role of Mikhail Kosis in the Turkish drama series Korolus Osman, has died at the age of 51.

The actor was found dead in his apartment in the Kağıthane district of Istanbul, Turkey, on September 5. His friend Ozlem E found him motionless on a chair in a room and immediately informed the emergency services.

According to his friend, she had been trying to contact the actor since September 3. In a statement to the police, she said that Serhat Mustafa Kilic was suffering from lymphatic cancer.

Initial examinations did not find any signs of physical assault or injury on the actor’s body, but police have launched an investigation into the incident. The body was taken to a hospital for a post-mortem to determine the final cause of death.

Serhat Mustafa Kilic began his artistic journey in theater in 1998. He had acted in several popular Turkish dramas, including Korolyush Osman, Suze and Mehmet Fatih, while his film Kach Yokosu also won an award at the Cannes Film Festival in 2014.