Three members of Cuba's athletics delegation at the World Championships in the United States, including former discus world champion Yaime Perez absconded, the country's sports institute said on Wednesday.
Defections by Cuban sports people while on international duty are commonplace as the communist nation has long prevented its athletes from turning professional.
Perez, 31, was the defending champion in Eugene, where she finished seventh, and a bronze medallist at the Tokyo Olympics in 2021.
Javelin thrower Yiselena Ballar, 19, and physiotherapist Carlos Gonzalez also disappeared.
The Jit online newspaper for Cuba's INDER sports institute described the defections as "serious indiscipline".
Both Perez and Ballar are believed to have escaped during a stopover in Miami while on the return journey to Cuba.
Cuba suffered its worst ever result at an athletics world championships, failing to win a single medal.
More than two dozen Cuban sports people have defected this year alone, including Olympic long jump silver medalist Juan Miguel Echevarria, Olympic Greco-Roman wrestling champion Ismael Borrero and Olympic sprint canoeing champion Fernando Dayan Jorge.
Last month, Olympic boxing champion Andy Cruz, considered by many experts to be the finest Cuban boxer of his generation, was caught trying to flee the island nation.
Cuba has slowly been opening up to professional sport in a bid to discourage the defections.
In April, communist authorities finally allowed boxers to take part in professional boxing competitions, leading to a team match against Mexico, which the Cubans won 6-0 with five knockouts, even without Cruz.
Other sports such as baseball have also embraced limited professionalism recently as in May Cuban authorities reached an agreement with the sport's international governing body, the WBSC, to allow Cuban baseballers to manage their own professional contracts with clubs in foreign leagues.
Cuba is suffering its worst recession in three decades, partly provoked by the coronavirus pandemic and the ramping up of US sanctions under former president Donald Trump, which has led to mass migration.