A new toxicology analysis conducted by officials in Costa Rica has confirmed that 14-year-old Miller Gardner — son of former New York Yankees player Brett Gardner — passed away due to carbon monoxide poisoning. The results were released following a thorough examination after the teen's sudden death while on vacation with his family.

Testing revealed that Miller's blood contained a carboxyhemoglobin saturation level of 64%, according to Costa Rican authorities. Experts consider any levels above 50% to be fatal. No additional toxic substances or narcotics, including fentanyl, were detected in his system.

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NEW YORK, NY - MAY 22: Brett Gardner #11 of the New York Yankees walks back to the dugout between innings against the Texas Rangers during their game at Yankee Stadium on May 22, 2015 in New York City. Al Bello/Getty Images

Miller reportedly died in his sleep during the early hours of March 21. The family was staying at a luxury resort in Costa Rica at the time. While the property has not released a statement in direct response to the toxicology findings, it previously claimed that any high carbon monoxide levels were confined to a nearby machine room, not the suite where Miller was staying.

According to a source familiar with the investigation in Costa Rica, the family dined at a local restaurant near the resort the evening before Miller died. After returning to the hotel, they began to feel unwell.

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CLEVELAND, OH - OCTOBER 11: Brett Gardner #11 of the New York Yankees reacts after being thrown out at second while attempting to steal in the sixth inning against the Cleveland Indians in Game Five of the American League Divisional Series at Progressive Field on October 11, 2017 in Cleveland, Ohio. Gregory Shamus/Getty Images

A hotel representative told investigators that staff responded quickly to the medical emergency. "The staff dispatched a medical team immediately, including a licensed doctor, which arrived to handle the emergency situation," the spokesperson stated.

In a heartfelt message, the Gardner family shared, "Miller was a beloved son and brother and we cannot yet comprehend our life without his infectious smile. We are so thankful to all who have reached out to offer support and encouragement during this difficult time and we are confident our faith, family, and friends will help us navigate this unimaginable loss."