QUEPOS, Costa Rica — Costa Rican authorities are investigating whether former Yankee star Brett Gardner’s teen son died from an allergic reaction to medication he was given for food poisoning.

Miller Gardner, 14, was found dead in his bed at an upscale beach resort on Friday morning after he and his family fell ill after eating at a restaurant near their hotel. 

Five days later, the teen’s sudden death remains a mystery.

Miller Gardner died while on vacation with his family in Costa Rica on March 21, 2025.

Investigators are now probing the possibility that the teen had an allergic response to medication he may have been given when the family was treated by a doctor after reporting feeling sick to the resort, sources told ABC News.

“The hotel staff dispatched a medical team immediately, including a licensed doctor, which arrived to handle the emergency situation,” the $2,000 per night Arenas Del Mar Resort in Manuel Antonio said in a statement to the outlet.

The resort added that protocol “does not allow for hotel staff to provide any medications to guests.”

The teen’s death has put a chill over the resort town, where the local economy is driven largely by international tourism.

“It’s a hard topic,” a bartender at one hotel told The Post. “Everyone is worried because someone — a chef or someone who made the food — could go to jail. People are talking about it.”

Miller Gardner died while on a family vacation in Costa Rica. Facebook / Miller Gardner

He added: “Everyone in town is nervous.”

Restaurants where the Gardner family ate earlier in their vacation have distanced themselves from the tragic incident, including the high-end Le Papillon, where they dined three nights earlier.

The Arenas Del Mar resort issued a statement saying they did not eat at one of their restaurants the night before Miller died, while staffers at the eatery where the family reportedly ate that night denied any knowledge of the boy’s death.

The Gardner family at a Georgia Bulldogs game posted to Instagram on Oct. 5, 2024. Instagram / Hunter Gardner

Meanwhile, authorities are hoping toxicology and other tests will determine what killed Miller — with those results expected to take as long as three months, police said. 

Costa Rica’s Judicial Investigations Police said results of toxicology, histology and neuropathology tests for Miller will be delayed “due to the high demand for autopsies being performed in the country due to the increase in homicides.”

The country’s homicide rate hit an all-time high of 17.3 per 100,000 people in 2023, raising fears in the popular tourist destination, the English-language outlet Tico Times reported.

The spike in violence, with more than 900 killings in the country of 5.1 million people, is due to a turf war between rival immigrant gangs, Cronkite News reported.

While still lower than many major US cities, the murder rate prompted a “Level 2” travel alert from the US State Department in December warning travelers to use “increased caution.”

“Exercise increased caution in Costa Rica due to crime,” the alert said. “Petty crime is common throughout Costa Rica. Violent crime, including armed robbery, homicide, and sexual assault, also affects tourists.”

High-end resorts like that one where Brett Gardner, his wife Jessica, and their sons, Miller and Hunter, were vacationing remain relatively safe from crime, with many hotels having security guards on duty.

Miller Gardner fell ill after dinner the night before his death and was treated by the hotel’s medical staff. 

The Arenas Del Mar Beachfront and Rainforest Resort in Costa Rica. Arenas Del Mar Beachfront & Rainforest Resort

Costa Rican officials said Tuesday a preliminary examination of the teen’s body found that his airways were not obstructed. 

Investigators had initially believed the teen choked to death because he had vomited in his bed.

It’s not yet clear whether Miller’s death was linked to food poisoning.

Brett Gardner, 41, was the Yankees’ outfielder for 14 years until he retired after the 2021 season. The fan favorite and former All-Star was part of the 2009 World Series championship team.

The team announced this week that a moment of silence will be observed in Miller’s memory when the Bronx Bombers kick off their season on Thursday.