Miller, 14, passed away on the morning of Friday, March 21, while on a family vacation in Costa Rica, as previously announced by the Yankees.
The official cause of death for Miller, son of former New York Yankees player Brett Gardner, was confirmed on Wednesday, April 2, as carbon monoxide exposure.
According to Randall Zúñiga, director of Costa Rica’s Judicial Investigation Department (OIJ), Miller tested positive for carboxyhemoglobin, a compound formed when carbon monoxide is inhaled. Medscape describes carboxyhemoglobin as a stable complex in red blood cells that results from exposure to the gas.
A carboxyhemoglobin level exceeding 50% is considered fatal, and Miller’s measured 64%, Zúñiga stated via the Associated Press. The autopsy also revealed a “layer” on his organs, further indicating the presence of the toxic gas.
“It’s important to note that adjacent to this room is a dedicated machine room, where it’s believed there may be some type of contamination toward these rooms,” Zúñiga added.
However, last Monday, Arenas Del Mar Beachfront & Rainforest Resort, where Miller and his family were staying, disputed the agency’s findings, denying the presence of “high levels of carbon monoxide contamination” and asserting that the gas levels in the room were “non-existent and non-lethal.”
PEOPLE has reached out to the hotel for further comment regarding the OIJ’s findings.
