Saud Mukhtar Al Hashimi, a well-known Islamist critic of Saudi Arabia’s absolute monarchy, was detained in February with nine others.
His family said they believed his calls for a constitutional monarchy and elected parliament were behind the arrests, not his championing of Iraqi and Palestinian causes.
They said Hashimi organised weekly political discussion groups which often gathered over 200 people in a country where political parties are banned.
The US-allied Saudi authorities have often cracked down on perceived threats to their rule, arresting scores of clerics who demanded reforms and an end to corruption in the 1990s and trying three reformist intellectuals in 2005.
"He interprets the detention as being because he is an activist with strong opinions on domestic reform," said Hasna Zahrani, wife of the 45-year-old doctor.
"He said bureaucratic corruption among some officials should be sorted, but bringing down the (ruling) family or replacing it with another-he rejected that." The authorities have declined to give any details on the arrests but said the investigations against the men, who are being held in solitary confinement, were ongoing.
Last week a separate group of reformers were released in Riyadh after months of detention without charge.
Officials have not made clear whether the charges against the Jeddah reformers concern links to insurgents in Iraq or Palestinian group Hamas, which the United States and its allies tried to starve of funds after it won elections in 2006.
Hashimi’s family and lawyer Bassem Alim, a reform activist, recounted a gathering at Hashimi’s home in late 2006 where dozens gave money to visiting Hamas official Mahmoud Al Zahhar.
Alim said Zahhar came with a government escort and that an Interior Ministry representative gave a donation. Iraqi Sunni Arab leader Harith Al Dari also visited Hashimi’s home.
Dari, who says the Sunni insurgency against US forces in Iraq is legitimate, was warmly received by the Custodian of the Two Holy Mosque King Abdullah bin Abdulaziz last year.
