The Cuban leader has admitted that a Jewish American man who was arrested in Havana two and a half years ago and is now behind bars is not a spy.
According to the Associated Press, President Raul Castro acknowledged that 62-year-old Alan Gross, who speaks barely any Spanish, "was no spy."
He made the comment during a meeting with US Senator Patrick Leahy, who visited Mr Gross in his cell at a Cuban military prison last week.
However the strange case of Mr Gross is far from over, as Mr Leahy said his offer to take the prisoner home was declined. "We have a long way to go," he said.
Mr Gross was detained in December 2009 while working as a contractor for a US international development programme, having previously visited Cuba five times under his own name.
He claimed that he was on the Communist-run island to support the Cuban Jewish community by providing them with internet access, but the authorities accused him of engaging in subversive activity. The 1,500-strong Jewish community did not back up his story, and ever since his detention there have been questions about the strength of his case.
A year ago, he was charged with "acts against the independence and territorial integrity of the state," and subsequently sentenced to 15 years behind bars for crimes against the state.
The Gross family has asked Mr Castro to agree to a pardon on humanitarian grounds, because of concerns over his health.
Mr Leahy, who took photographs of Mr Gross to bring home to his wife Judy, said: "He obviously wants to leave. He feels that his health has been endangered."