Oscar Elias Biscet, leader of the Lawton Foundation which organised four street demonstrations in Matanzas province this summer, was let go following a week behind bars after authorities cautioned him on the "dangerousness" of his chanting "God Loves You."
The government's intransigence contrasts with its leniency last year when, during a visit by Pope John Paul II, cardinals presented a clemency list to Havana which was processed in less than a month.
But the four most outspoken opponents of President Fidel Castro, who were sentenced for up to five years last March for "contempt of authority" and "anti-government propaganda", remain incarcerated.
Elizardo Sanchez Santacruz, the prominent Cuban opposition leader, said 300 dissidents remain in prison, many of them labour activists. He predicted that there might be another amnesty prior to the Ibero-American Summit scheduled for November in Havana.
Two visiting US senators, who had been promised access to any Cuban citizen during their tour last week, were repeatedly denied interviews with Marta Beatriz Roque, an economist who is serving a three-and-a-half- year term for leading an unprecedented hunger strike earlier this year.
One of the senators, minority leader Tom Daschle, urged President Bill Clinton to consider lifting the 1961 trade embargo to allow in essential food and medications.
White House spokesman David Leavy confirmed that Mr Clinton is willing to consider bipartisan talks about softening the sanctions against Mr Castro's Communist regime.
"When Congress resumes, certainly we will discuss this with both parties," he said. This is expected to become a major issue in the upcoming US presidential race, guaranteed to raise heated arguments within both parties.
The indiscriminate nature of the embargo has brought repeated criticism from the UN General Assembly, Pope John Paul II, and governments around the world for nearly four decades.
"The embargo has become counterproductive to the promotion of human rights," said Jose Miguel Vivanco, a Human Rights Watch activist. "It has divided the international community and enabled Castro to justify repression on anti-imperialist grounds."
A report, released last month, by Human Rights Watch condemned the repressive Cuban laws that criminalise free expression and association. It denounced an ill-defined provision against "dangerousness", used to detain Cubans who have not committed any crime.
A dearth of independent judges and restricted access to attorneys compromises the right to a fair trial on the island, it said. The government's failure to ensure due process makes its use of the death penalty especially troubling, according to the report, which notes recent executions by firing squad.