Cowie died on Sept. 3 from acute and chronic alcohol use in Brooklyn, New York, Julie Bolcer, a spokesperson for the NYC Office of Chief Medical Examiner, confirms to PEOPLE.
His manner of death has been determined as natural, Bolcer says.
Cowie was found unconscious on the morning of Sept. 3 at an apartment in the East Flatbush neighborhood, police previously said, according to NBC New York. He was pronounced dead at the scene.
Prior to his death, Cowie worked alongside Joe Exotic, whose legal name is Joseph Maldonado-Passage, as one of the zookeepers at the ill-fated G.W. Exotic Animal Memorial Park in Wynnewood, Oklahoma. His involvement with the zoo was documented on Tiger King, which premiered on Netflix in 2020.
Maldonado-Passage was found guilty in a murder-for-hire plot to kill his rival, big cat activist Carole Baskin. He was sentenced in 2020 to serve 22 years in prison for that and other crimes, which included killing tigers to make room for more big cats at his exotic animal park.
Cowie testified against Maldonado-Passage — whose original sentence was vacated in July — in the case.
According to authorities, starting in July 2016, Maldonado-Passage repeatedly tried to hire people to murder Baskin, who owns a tiger refuge in Florida and won a multimillion-dollar judgment against his Oklahoma zoo.
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Maldonado-Passage eventually gave a man $3,000 to travel from Oklahoma to South Carolina and on to Florida to kill Baskin, "with a promise to pay thousands more after the deed," according to the U.S. Attorney's Office.
The case has been sent back to an Oklahoma City judge for resentencing.
Many of the subjects on Tiger King have befallen hard times since the series was released on the streaming network, including Jeff Lowe and his wife Lauren, who had more than five dozen big cats seized by federal authorities from their Oklahoma zoo after they were accused of violating the Endangered Species Act (ESA) in May.