The number of political prisoners held in Cuban jails has dropped to an all-time low, continuing a gradual trend in recent years of releasing them, a human rights group report says.

A bi-annual report, issued by the independent Cuban Commission for Human Rights group on Monday, said the communist government of Cuba now holds 167 political prisoners, down from 201 at the end of 2009.

The commission said that after the 1959 revolution that put Fidel Castro in power, the number of political prisoners had peaked six years later at 15,000.

But that number has steadily declined, especially in the past seven years, after the government realised that "it does not need to have so many political prisoners to maintain almost complete social control," Elizardo Sanchez, a spokesman for the rights commission, said.

Sanchez said the group's findings also indicate that the government is readying to free about 40 more jailed dissidents.

"We are receiving information from the prisons that they are interviewing them, preparing them and asking what they plan to do when they get out," he said.

Cuban pressure

The Cuban government has been under increased pressure to free political prisoners, from both domestic and international quarters.

The Catholic Church entered into dialogue with the government in recent months to try to secure the release of some of the ailing political prisoners, and the Chilean president, Sebastian Pinera, has said his administration would also approach Cuba.

Miguel Angel Moratinos, the Spanish foreign minister, arrived in Havana, the Cuban capital, on Monday to support the church's efforts and attempt to save the life of a Cuban hunger-striker.

Cuban media reported earlier in the weekthat Guillermo Farinas, who has been on a voluntary fast for more than 130 days to demand the release of seriously ill political prisoners, is in danger of dying.

Although Raul Castro, Cuba's president, has labelled Farinas a common criminal and said the government would not yield to "blackmail", Spain's foreign minister hopes to secure the release of the 26 political prisoners in poor health, thereby meeting Farinas' demand and allowing him to end his hunger strike.