HAVANA -- Oscar Espinosa Chepe, a high-level Cuban economist and diplomat who broke with Fidel Castro's government in the 1990s and was imprisoned for dissident activities, died in Spain on Monday. He was 72.

Espinosa died in Fuenfria Hospital in Cercedilla, just north of Madrid, where he had been undergoing treatment for chronic liver disease since March. His wife, Miriam Leiva, said she was not sure whether his remains would be repatriated.

"We had hoped the disease could be stopped, but it could not be," Leiva said. "He always wanted to return to Cuba."

Espinosa was one of 75 writers and political activists locked up in 2003 during the Black Spring, a notorious crackdown on dissent that provoked international criticism and EU sanctions lasting five years.

Little known at the time of his imprisonment, Espinosa was sentenced to 20 years but released after 19 months on medical humanitarian grounds, on his 64th birthday.

By then his name was more familiar in part thanks to the work of Leiva, who helped found the Ladies in White protest group to press for their husbands' release.

Espinosa said the government had made a mistake by locking him and the others up, and vowed they would not be silenced. The Cuban government frequently accuses island dissidents of accepting money from Washington to undermine the government, but Espinosa frequently denied being a "mercenary."

"We are nonviolent people who have not committed any crime," he told reporters in November 2004 at his and Leiva's tiny Havana apartment, always overflowing with the books, papers and statistical reports they used to write about Cuba's complex and troubled economy.

There was no apparent mention of his passing in Cuba's state-controlled media, and government officials did not respond to a request for comment.

Espinosa had suffered from liver problems for years and in the early 2000s was diagnosed with cirrhosis. He was also hospitalized in August 2012.

"My health problems are from before I was imprisoned, but the conditions of the prison contributed to making them worse," the gray-haired, soft-spoken Espinosa told The Associated Press shortly before he traveled to Spain for medical treatment.

He was born Nov. 29, 1940, in the central province of Cienfuegos, and along with many of his generation was infused with revolutionary fervor following Fidel Castro's 1959 Cuban Revolution.

He graduated with a degree in economics from the University of Havana in 1961 and began a long career of mid- and high-ranking posts in the government, including as counselor to then-Prime Minister Castro in the `60s and later as head of the powerful Office of Agrarian Reform.

Espinosa also was a member of the State Committee for Economic Collaboration, specializing in a handful of Soviet bloc nations, and did a stint as Cuba's economic attache in Yugoslavia.

He took up a position at the National Bank of Cuba upon his return in the 1980s, but increasingly found himself at odds with government policy.

According to Espinosa's account, in the early 1990s, after voicing disagreement with the country's economic policies, he was denounced by a colleague, publicly sanctioned and ultimately fired.

From his later writings, it was clear that Espinosa believed the Communist government wielded excessive control over the economy and he was a strong critic of corruption and bureaucracy.

He reinvented himself as a writer about the Cuban economy, publishing articles and books in the United States, Spain and elsewhere, and doing some work for Radio Marti – U.S.-funded broadcasts aimed at Cuba that Havana bitterly objects to as an intrusion on its sovereignty.

"He never wavered, and made his opinion about human rights known to the world," Ladies in White leader Berta Soler said Monday.

However Espinosa also vocally opposed the U.S. embargo and economic sanctions against the island, saying it gave the Cuban government an excuse for its shortcomings and the restrictions it placed on Cubans.

Espinosa's independent, critical voice touched a generation of Cuba scholars around the world, one colleague said in a prologue to his book.

"Oscar's admirable labor in his numerous, documented and brave works on the economy and social aspects in Cuba have inspired and influenced the work of many Cuban economists in the exterior," the U.S.-based economist Carmelo Mesa Lago wrote.

Espinosa's death is the third significant loss for Cuba's tiny community of outspoken dissidents in as many years, following the passing of Ladies in White co-founder Laura Pollan in 2011 and Varela Project author Oswaldo Paya the following year in a car wreck.

"The Ladies in White are in mourning," Soler said. "We have lost a brother in arms, a man who devoted his life to a democratic Cuba."

___

Associated Press writers Jorge Sainz and Ciaran Giles in Madrid contributed to this report.

___

Andrea Rodriguez on Twitter: www.twitter.com/ARodriguezAP

Also on HuffPost:

Loading Slideshow...
  • This April 24, 2012 photo shows a view of Cuba's southeastern coastline and the Caribbean Sea from the top of the Castillo del Morro San Pedro de la Roca, a 17th century Spanish fortress that protects the entrance to the harbor in Santiago de Cuba, Cuba. The fortress was originally designed to fend off pirate attacks. (AP Photo/Kathy Willens)

  • In this picture taken on April 26, 2012, performers dance to live music at Casa de la Trova or House of Troubadours in Santiago de Cuba, Cuba. Music is an integral part of the Cuban culture. One doesn't have to travel far in the downtown section of Havana or Santiago, Cuba's second largest city, to hear the sounds of live music spilling out of nightclubs, bars and social clubs. (AP Photo/Kathy Willens)

  • This April 26, 2012 photo shows performers dancing to live music at Casa de la Trova, house of troubadors, in Santiago de Cuba, Cuba. Music is an integral part of Cuban culture, particularly in Santiago de Cuba, birthplace of composer Compay de Segundo, who was well known before, but became an international celebrity when the Ry Cooder film, "The Buena Vista Social Club" was released. (AP Photo/Kathy Willens)

  • This April 24, 2012 photo shows a group of men playing a game of dominoes at a park in Santiago de Cuba, Cuba. (AP Photo/Kathy Willens)

  • In this picture taken Sunday April 22, 2012, young men and women dance in the front row during the Cuban National Baseball Series between the Holguin home team and the Havana-based Metropolitanos, a farm team of the better-known Industriales at the local stadium in Holguin, Cuba. (AP Photo/Kathy Willens)

  • In this Saturday April 21, 2012, men bearing their own bottles crowd around a beer truck where they can purchase refills for five Cuban pesos, in the seaside town of Gibara, Cuba. (AP Photo/Kathy Willens)

  • This April 24, 2012 photo shows young dance students performing for American visitors at the Jose Maria Heredia Vocational Arts school in Santiago de Cuba, Cuba. The school is dedicated to educating eight to 18 year-olds. Students identified as talented who live outside Santiago may attend. All students are provided free tuition, room and board. They may return home every other weekend to visit their families. (AP Photo/Kathy Willens)

  • In this picture taken on April 21, 2012, a young girl rides on a carousel of a street fair near the harbor in the seaside town of Gibara, Cuba. (AP Photo/Kathy Willens)

  • This April 26, 2012 photo shows performers dancing to live music at Casa de la Trova, house of troubadors, in Santiago de Cuba, Cuba. Music is an integral part of Cuban culture, particularly in Santiago de Cuba, birthplace of composer Compay de Segundo, who was well known before, but became an international celebrity when the Ry Cooder film, "The Buena Vista Social Club" was released. (AP Photo/Kathy Willens)

  • In this picture taken on April 25, 2012, a man puffs on his cigar during a meeting of a CDR or Committee for the Defense of the Revolution at a neighborhood in Santiago de Cuba, Cuba. (AP Photo/Kathy Willens)

  • In this photo taken Monday April 23, 2012, pedestrians follow a hearse during a funeral procession on a road near Santiago de Cuba. (AP Photo/Kathy Willens)

  • In this picture taken on April 17, 2012, a woman sweeps her stoop beside a sign that reads in Spanish: "Long Live the CDR" in Havana, Cuba. The CDR or Committee for the Defense of the Revolution are neighborhood watch organizations that do everything from making sure that residents show up for the anniversary of the revolution to promoting vaccination campaigns, running blood banks, and conducting hurricane evacuation drills. (AP Photo/Kathy Willens)

  • This April 24, 2012 photo shows students raising their hands to answer their teacher's questions in front of a portrait of Ernesto "Che" Guevara, the Argentine-born co-founder of the Cuban revolution, at the Jose Maria Heredia Vocational Arts school in Santiago de Cuba, Cuba. The school is dedicated to educating musically- talented eight to 18 year-olds, some of whom come from surrounding areas. The Cuban government provides free tuition, room and board. Students are allowed to return home every two weeks to visit their families.(AP Photo/Kathy Willens)

  • In this picture taken on April 17, 2012, a musician rehearses beside a louvered window at a restaurant in Old Havana, Cuba. (AP Photo/Kathy Willens)

  • In this picture taken Monday April 23, 2012, a sign inside a school in Bayamo, Cuba, promotes children's rights to a free education, among other things. Cuba's literacy rate for those 15 years and older, at 99.8%, is among the highest in Latin America, second only to that of Argentina, according to statistics from the World Bank. (AP Photo/Kathy Willens)

  • In this picture taken April 17, 2012, a young boy rests on a bicycle cart as workers slide construction materials onto the cart for transport through Old Havana, Cuba. Restoration as well as new construction are a frequent sight in the city. (AP Photo/Kathy Willens)

  • In this photo taken Monday April 23, 2012, primary school students walk past a mural depicting heros of Cuba's independence from Spain, including Cuban patriot Francisco Vicente Aguilera, right, who later supported Carlos Manuel de Cespedes in the revolt against Spain, in Bayamo, a colonial town in Oriente province. The color of children's uniforms denotes their educational level. (AP Photo/Kathy Willens)

  • In this photo taken Monday April 23, 2012, a man climbs under the engine of his Russian-made car while repairing it in Bayamo, Cuba. Since cars are expensive, many of the ones on the streets have old bodies but have engines that have been repaired and replaced multiple times. (AP Photo/Kathy Willens)

  • In this Saturday April 21, 2012, residents seek shade beneath a sculpture of a sailfish in the seaside town of Gibara, Cuba, Saturday, April 21, 2012, during the annual international Cine Pobre, the Poor People's International cinema festival that is held in the town. (AP Photo/Kathy Willens)