Erik Cowie, the onetime Joe Exotic ally who cared for the animals in his zoo, died of acute and chronic alcohol use, the N.Y.C. Medical Examiner’s office announced Monday.

The cause of death was confirmed to Variety by Julie Bolcer at the NYC Office of Chief Medical Examiner.

On Sept. 3, Cowie, 52, was found dead in a Brooklyn apartment by “police responding to a 911 call of an unconscious male inside of 21 East 55 Street in the confines of the 67 Precinct.” According to the NYPD’s official statement, EMS was on scene and pronounced the man dead.

Cowie was a zookeeper at Exotic’s G.W. Zoo in Wynnewood, Okla., and was featured on Netflix’s hit docuseries “Tiger King: Murder, Mayhem and Madness.” He was charged with a DUI in Oklahoma in May, and spoken on the show about his struggles with alcohol.

Even after Exotic went to prison, Cowie remained at the zoo, although his loyalties to the larger-than-life owner had shifted. During the trial, Cowie testified that he had seen Exotic have animals killed.

On the “Tiger King” after-show “The Tiger King and I,” Cowie spoke about his regrets working with Exotic.

“A lot of times when we put cats down, they used me because just by my appearance or my voice, I could get a cat up the side of a cage, where we can dart it and tranquilize it so they could be put down and stuff,” he said. “You know, those cats trusted me up until the end, and somehow, sometimes I swear they’re like, ‘Dude, you let me down’ kinda thing. I could see it in their face and their eyes.”

“Tiger King: Murder, Mayhem and Madness” was a massive hit for Netflix, with the streamer saying it was sampled by 64 million households worldwide in the first month on the platform.

J. Kim Murphy contributed to this report.