The Saudi Arabian authorities must release a prominent human rights activist who is reported to have been on hunger strike for five weeks in protest at his continuing unfair imprisonment, Amnesty International said.Mohammed Saleh al-Bajady, co-founder of the unregistered NGO the Saudi Civil and Political Rights Association (ACPRA), has reportedly refused to take water since last weekend – heightening fears for his health.He has been held since his arrest on 21 March 2011, a day after he attended a protest in the capital Riyadh by families of detainees arbitrarily held.Charged with being a member of ACPRA, harming the reputation of the state and having banned books in his possession, Mohammed Saleh al-Bajady has been on trial since August at the Specialized Criminal Court, which was set up to try terrorism and security-related offences.”Mohammed Saleh al-Bajady is a prisoner of conscience held solely for the peaceful exercise of his rights to freedom of expression, assembly and association. All charges against him should be dropped and he should be released immediately,” said Hassiba Hadj Sahraoui Deputy Director of Amnesty International’s Middle East and North Africa programme.”His hunger strike makes his release all the more urgent as his health must be deteriorating with each day he refuses food and water.”According to reports from trusted sources, Mohammed Saleh al-Bajady has been on hunger strike in Riyadh’s al-Ha’ir prison since 11 March and has been refusing to take water since 7 April. He has also refused family visits and phone calls.On 10 April, an interior ministry spokesman told news agencies that Mohammed al-Bajady was not on hunger strike and that he is in good health.His legal defence team have asked to be allowed access to check his condition for themselves. They have not been allowed to see him since his arrest or to attend his trial, as their right to represent him is not recognized by the court. They were not let in to hearings despite standing outside the court for hours.Mohammed Saleh al-Bajady was arrested in the town of Buraydah, in the province of Qasim, north of Riyadh on 21 March 2011.He was then taken to his home and office by uniformed agents and men in civilian clothes believed to have been members of the interior ministry’s internal security service where they confiscated books, documents and laptops from home and his office.The day before his arrest, Mohammed Saleh al-Bajady had taken part in a protest outside the Interior Ministry in Riyadh.The protesters were calling for the release of male relatives, who have been detained for years without charge.A number of men and women at the protest were arrested. The women were said to have been released after they were made to fingerprint statements confirming that they had attended the protest. The men are believed to be still detained.The Ministry of Interior confirmed the long-standing ban against demonstrations in Saudi Arabia on 5 March 2011, following protests by the minority Shi’a Muslim community in the Eastern Province and amid reports that further protests calling for reform were planned.A Ministry spokesperson said that security forces would take “all necessary measures” against those who attempt to disrupt order.Amnesty International has documented the repression of protesters in Saudi Arabia as well as the continuing repression of human rights activists, political dissidents and critics of the authorities, a number of whom have been detained and, in some cases, tried and imprisoned.While they are often accused, and convicted, of security-related offences, in courts set up to deal with security and terrorism-related offences, the acts which they are alleged to have committed generally appear to involve merely the peaceful exercise of their rights to freedom of expression, association and assembly.