The US created a text-message social network designed to foment unrest in Cuba, according to an investigation by the Associated Press news agency.
ZunZuneo, dubbed a «Cuban Twitter», had 40,000 subscribers at its height in a country with limited web access.
The project reportedly lasted from 2009-12 when the grant money ran out.
The US is said to have concealed its links to the network through a series of shell companies and by funnelling messages through other countries.
The BBC’s Sarah Rainsford in the Cuban capital of Havana says there is a thirst for information on the island, which has no independent media.