For five years, independent journalist Bernardo Arévalo Padrón has issued clandestine reports on inhuman conditions from his cell at a prison in southern Cuba.

But a recent letter in which Arévalo Padrón for the first time expressed fear for his life has raised concern among human rights groups, unleashing an effort to bring international attention to his case.

''We are very worried,'' Ricardo González, president of an independent group of journalists in Havana, said by phone. ``We are making our concern public because it is the only way we can try to prevent anything from happening to him.

''We want to, first of all, save his life,'' Gonzalez said. ``Secondly, we want him to be given his freedom.''

Arévalo Padrón, 34, was arrested in 1997 after calling President Fidel Castro and Vice President Carlos Lage liars in a telephone interview with a radio program in Miami. He was sentenced to six years and is serving the term at a prison in Cienfuegos called Ariza.

Known for his outspoken manner and unwavering beliefs, Arévalo Padrón has consistently vowed to continue his journalistic work even behind bars. But that conviction has led to threats from prison authorities, according to a letter sent last week to other independent journalists on the island.

According to colleagues, Arévalo Padrón was told by prison authorities that if he did not stop sending bulletins from the jail, family visits for all of the prisoners in his prison unit would cease.

Supporters said that could lead to violent attacks from the other inmates.

''The international community should be concerned about his case,'' said Vladimiro Roca, a prominent dissent who was released from the same prison in May after serving nearly five years on charges of sedition. ``He is a prisoner of conscience. He is in jail because of his ideas.''

The Inter-American Press Association has issued a statement saying the threat by prison authorities has put the journalist's life at risk.

''We are afraid that a measure of that nature would incite reprisals from the common prisoners,'' the IAPA said.

Similar statements have been issued by other international organizations.

Arévalo Padrón is among an estimated 300 political prisoners in Cuban prisons.

Meanwhile, efforts are under way to bring another prominent Cuban dissident to Washington next month for an award issued by the National Democratic Institute. Oswaldo Payá Sardiñas, coordinator of a grassroots movement known as the Varela Project, will be the first Cuban to receive such an honor.

The Varela Project, an initiative that calls for a referendum on sweeping democratic reforms, has been recognized internationally as the largest non-government grassroots campaign since Castro rose to power in 1959. It was given unprecedented legitimacy by former President Jimmy Carter during a visit to Havana in May.

''It's an award recognizing the courage of the Cuban people and their commitment to the universal principles,'' said Kenneth Wollack, institute president. ``The Varela Project unleashed the beginning of a genuine movement. It set off a democratic spark in the country.''

The institute, founded in 1982, provides assistance to civic and political leaders to strengthen and expand democracy worldwide. Payá, who will share this year's honor with the Organization of American States, is being recognized for his work dedicated to democracy and human rights.

Other democratic movements recognized include the Dominican Republic's Participación Ciudadana, for its role in preventing violence and contributing to the peaceful resolution to the 1994 electoral crisis; Nicaragua's Centro de Estudios Estratégicos, for helping to create the first civilian-led defense ministry in 1996; and Mexico's Alianza Civica , for promoting electoral reforms that ushered in the historic 2000 elections.