HAVANA — The Cuban spy traded to the U.S. for jailed Cuban intelligence agents but out of contact with his family for nearly a month is in the U.S. and is doing fine, his sister told The Associated Press in an interview Tuesday.

Vilma Sarraff, who lives in Spain, said her 51-year-old brother Rolando called her for the first time since his Dec. 17 release amid a big thaw in U.S.-Cuban relations. The brother told her he is "free and doing fine."

She declined to say where he is living in the U.S. or anything else about her brother, a former cryptologist in Cuba's Directorate of Intelligence who helped the U.S. crack a Cuban spy network in Florida.

Sarraff's mother, Odesa Trujillo, told the AP that she and her husband had heard nothing from their son since his release but were optimistic about getting news about him within days. She said Sarraff's 79-year-old father, also named Rolando, had come down with pneumonia since his son's release.

The younger Rolando Sarraff was identified in December by a former U.S. official as the released spy who President Barack Obama hailed as one of Washington's most valuable assets when he announced the thaw in relations. But U.S. and Cuban officials never disclosed where he went after his release to Vilma Sarraff or her parents, who live in Havana.

Vilma Sarraff spoke a day after the U.S. confirmed that Cuba had freed 53 political prisoners promised their liberty as part of the historic accord between Obama's administration and the Cuban government.

Before his downfall, the younger Rolando Sarraff helped the U.S. crack the "Wasp Network," a Florida-based Cuban spy ring that included members of the so-called Cuban Five, the last three of whom were released in exchange for him.

The Cuban Five were convicted in 2001 of being unregistered foreign agents, and three also were found guilty of espionage conspiracy for failed efforts to obtain military secrets from the U.S. Southern Command headquarters.

The elder Rolando Sarraff is a retired lieutenant colonel in Cuba's armed forces and a former journalist with the state news agency Prensa Latina. He and his wife last month claimed ignorance of the details of their son's work, saying they only knew that he had been convicted of being a CIA spy nearly 20 years ago.

The younger Sarraff was arrested by state security agents in 1995.