The death of Miller Gardner, the 14-year-old son of former New York Yankees outfielder Brett Gardner, is being investigated as related to possible carbon monoxide poisoning, Randall Zuniga, director of Costa Rica's Judicial Investigation Department (OIJ), said in a news conference Monday.
An OIJ spokesperson confirmed to ESPN by text message that investigators believe the death to be accidental rather than the result of foul play.
"Furthermore, this investigation has been closely coordinated with the FBI in the United States," Zuniga said at the news conference.
Zuniga also said that tests were conducted in "the room the family was staying" on Friday -- a week after Miller Gardner was found in his hotel room in a popular resort district -- when "high emissions of carbon monoxide contamination were detected.