Cuban Parliament Speaker Ricardo Alarcon has called on the US government to release five Cuban men serving long prison terms on espionage conspiracy charges after a US federal appeals court threw out their convictions and sentences.

A Cuban spy who dug ditches and fixed vents for six years while counting planes at a US Navy base in the Florida Keys has received a life prison sentence.

Five Cuban agents have been convicted in Miami of plotting espionage against the United States, and the leader of the group faces a life sentence for his role in a Cuban air force MiG attack that killed four US airmen.