The technical team arrived on Tuesday “as part of their thorough and independent investigation” into the maritime incident, the official told AFP on condition of anonymity.

The visit comes amid rising tensions between the US and communist-run Cuba, with US President Donald Trump imposing a de facto oil blockade since January and talking about “taking” Cuba.

Five members of the Florida-registered boat’s crew died while Cuban authorities charged the five survivors with terrorism, accusing them of bringing weapons and seeking to destabilise the government in Havana.

The shoot-out occurred on Feb 25 when a coast guard boat approached the vessel in Cuban waters to demand identification, and the crew responded by opening fire, according to Cuban authorities.

The US embassy official declined to give more details about the FBI’s visit.

The official cited February remarks by US secretary of state Marco Rubio, in which he said the “majority of the facts being publicly reported are those by the information provided by the Cubans.”

“We will verify that independently,” Rubio said. “But we’re going to find out exactly what happened here, and then we’ll respond accordingly.”

Cuban authorities said the 10 suspects were Cubans residing in the US, and that most had criminal records.

At least two of them were US citizens, according to a US official.