Oscar Elias Biscet, one of Cuba's best-known dissidents, was sentenced to 25 years in prison on Thursday as part of a widespread crackdown by the Cuban Government.
Oscar Elias Biscet: One of many dissidents recently locked up
Mr Biscet, a doctor who has engaged in acts of civil disobedience
in the past, was charged with working with the United States to subvert the government.
He is one of 75 dissidents who have recently been sentenced to up to 28 years in prison for opposing President Fidel Castro's rule.
What has been the biggest crackdown on dissidents in years began last month after journalists attended a workshop at the residence of the head of the US Interests Section in Havana, James Cason.
Already in jail
Cuban Foreign Minister Felipe Perez Roque defended the government's actions, saying Cuba was protecting its independence from a United States-funded conspiracy.
But Mr Biscet's wife, Elsa Morejon, said: "My husband is innocent... this cruel sentence will not weaken his will or conscience because they have condemned a profoundly humane man."
He already in jail on lesser charges for opposing President Castro's government when authorities started rounding up opponents last month.
Another prominent dissident, Elizardo Sanchez Santa Cruz, president of the Cuban Committee for Human Rights and National Reconciliation, said the aim of the crackdown was to "silence the dissident movement".
But Mr Perez Roque blamed Mr Carson for helping to stir up trouble.
"We have been patient, tolerant, but the activities of Cason,
the head of the US Interests Section in Cuba, have forced us to
enforce our laws. We had no alternative," he said.
This cruel sentence will not weaken his will or conscience because they have condemned a profoundly humane man
Biscet's wife Elsa Morejon
A White House spokesman said the recent crackdown on dissent was proof that President Castro's government remained a "totalitarian blight" on the region.
The EU Commission and human rights groups worldwide have also condemned the trials.
Washington and Havana have not had full diplomatic ties since 1961 when President Castro came to power.
Since then, the US has imposed tough sanctions on Cuba to undermine the communist regime.