The US is reportedly planning to indict Cuba's former president Raul Castro as Washington ratchets up pressure on the communist island.
Several US news outlets cited anonymous sources and Department of Justice officials as saying the case against Mr Castro, 94, is expected to focus on the downing of an aircraft.
CBS previously reported that the case relates to Cuba's deadly 1996 shoot-down of planes operated by humanitarian group Brothers to the Rescue.
The timing of any indictment was not clear as it would need to be approved by a grand jury. A Justice Department official told Reuters it could be imminent.
The development comes amid heightened tensions between Washington and Havana. The Trump administration has described Cuba's current communist-run government as corrupt and incompetent and is pushing for a regime change.
President Donald Trump has heaped pressure on the island, effectively imposing a blockade by threatening sanctions on countries supplying it with fuel, triggering power cuts and delivering blows to its economy.
Officials from the US and Cuba acknowledged earlier this year that they were in talks, but the negotiations appeared to founder as the US fuel blockade continued.
However, on Thursday, the Cuban government confirmed it had met with CIA director John Ratcliffe.
Mr Ratcliffe told intelligence officials in Cuba that the US was prepared to engage on economic security issues if the country makes “fundamental changes”, a CIA official said.
The US has previously used criminal cases against foreign political figures to justify military action.
In January, when the US military attacked Venezuela, the Trump administration described the raid as a “law enforcement operation” to bring president Nicolas Maduro to New York to face criminal charges.
Mr Trump in March threatened that Cuba “is next” after Venezuela.
Cuba is ruled by President Miguel Díaz-Canel and the Castro family, which has controlled the country since Fidel Castro and his brother Raul overthrew the Batista regime in 1959.
