"Signatories to this appeal exhort the custodian of the two holy mosques (Abdullah) to order the release of Matruk al-Faleh or his referral to a public and fair trial," 137 activists, including several women, said in a statement.
Faleh, who was arrested on May 19, has been on hunger strike, "and this puts his life at risk… since he suffers from diabetes and blood pressure," said the statement received by AFP.
Their appeal came two days after 14 human rights groups, mostly Arab, sent a petition to Abdullah urging the Saudi king to release Faleh and several other Saudi reformists, some of whom have been held for 16 months.
The charges against Faleh are unknown, but rights activists have linked his arrest to his defence of jailed reformist Abdullah al-Hamed and a statement he wrote after visiting him, which was critical of conditions in the jail.
Hamed and his brother Issa are serving jail terms of six and four months respectively on charges of inciting women to stage public protests, which are banned in Saudi Arabia.
Faleh is Hamed’s legal representative. The two men, along with a third reformist, had been pardoned by King Abdullah in August 2005 after they spent 17 months in jail for advocating a constitutional monarchy in oil-rich Saudi Arabia.
The petition also raised the case of nine activists who were arrested in February 2007 for alleged links to terror funding, eight of whom remain incarcerated without trial.
