Amnesty International has urged Cuban President Raúl Castro to immediately and unconditionally release all prisoners of conscience after a political activist died following a hunger strike.Orlando Zapata Tamayo was reported to have been on hunger strike in protest at prison conditions for several weeks before his death in Havana on Monday.”The tragic death of Orlando Zapata Tamayo is a terrible illustration of the despair facing prisoners of conscience who see no hope of being freed from their unfair and prolonged incarceration,” said Gerardo Ducos, Amnesty International’s Caribbean researcher. “A full investigation must be carried out to establish whether ill-treatment may have played a part in his death.”Orlando Zapata Tamayo was arrested in March 2003 and in May 2004 he was sentenced to three years in prison for “disrespect”, “public disorder” and “resistance”.He was subsequently tried several times on further charges of “disobedience” and “disorder in a penal establishment”, the last time in May 2009, and was serving a total sentence of 36 years at the time of his death.”Faced with a prolonged prison sentence, the fact that Orlando Zapata Tamayo felt he had no other avenue available to him but to starve himself in protest is a terrible indictment of the continuing repression of political dissidents in Cuba,” said Gerardo Ducos”The death of Orlando Zapata also underlines the urgent need for Cuba to invite international human rights experts to visit the country to verify respect for human rights, in particular obligations in the International Covenant on Civil and Political Rights.”Orlando Zapata Tamayo was one of 55 prisoners of conscience who have been adopted by Amnesty International in Cuba. The majority were among the 75 people arrested as part of the massive March 2003 crackdown by authorities against political activists. With no independent judiciary in Cuba, trials are often summary and fall grossly short of international fair trial standards. Once sentenced the chances of appeal are virtually nil.