A cause of death for Nicholas Brendon, known for being part of the Scooby gang on Buffy the Vampire Slayer, has been revealed.

According to a May 5 report from the Putnam County Coroner’s office obtained by People, Brandon died of atherosclerotic and hypertensive cardiovascular disease, with acute pneumonia and previous myocardial infarction as contributing factors. The “mechanism of death” was 90% blockage right coronary artery.

Brendon’s family revealed the actor died March 20 “in his sleep of natural causes.” He was 54.

In the report, coroner Todd Zeiner said law enforcement at the scene “found no obvious signs of foul play and assisted me with cataloging the scene. Nothing seemed out of place or disturbed.”

Brendon played the series regular role of Xander Harris opposite Sarah Michelle Gellar across Buffy the Vampire Slayer’s seven seasons on The WB and UPN.

After Buffy, Brendon went on to star in Kitchen Confidential as pastry chef Seth Richman alongside Bradley Cooper and Jaime King. He later recurred in Criminal Minds, Private Practice, and Faking It.

On the film side, Brendon starred in the 2000s comedy horror film Psycho Beach Party alongside Lauren Ambrose. Other film credits included Demon Island (2002), Unholy (2007), Blood on the Highway (2008), Big Gay Love (2013), and Coherence (2013), among others.

“We are heartbroken to share the passing of our brother and son, Nicholas Brendon. He passed in his sleep of natural causes,” read a statement from Brendon’s family on his Instagram on March 20. “Most people know Nicky for his work as an actor, and for the characters he brought to life over the years. In recent years Nicky has found his passion in painting and art. Nicky loved to share his enthusiastic talent with his family, friends and fans. He was passionate, sensitive, and endlessly driven to create.

“Those who truly knew him understood that his art was one of the purest reflections of who he was. While it’s no secret that Nicholas had struggles in the past, he was on medications and treatment to manage his diagnosis, and he was optimistic about the future at the time of his passing. Our family asks for privacy during this time as we grieve his loss and celebrate the life of a man who lived with intensity, imagination, and heart. Thank you to everyone who has shown love and support,” the statement concluded.

Armando Tinoco contributed to this report.