Saudi authorities detained prominent rights activist Waleed Abulkhair on Wednesday for setting up an "unauthorised" gathering hall where he held meetings with reformists in the absolute monarchy, his wife said.

Abulkhair, was taken into custody for setting up "an unauthorised diwaniah," or gathering place, and "due to his relations with the reformists and for hosting them in our diwaniah," Samar Badawi told AFP.

She said Abulkhair will be interrogated on Thursday by the public prosecutor of Jeddah, who will decide whether to release him on bail on keep him in custody.

The lawyer is already facing two trials over disrespecting the judiciary and having contact with foreign organisations.

In June 2012, Abulkhair was accused of "disrespecting the judiciary system... contacting foreign organisations and signing a petition demanding the release of detainees," some of whom were being held over suspected terror links, his wife said at the time.

Three months earlier, authorities banned him from travelling to the United States where he had been due to attend a forum organised by the State Department, he told AFP.

And in February 2011, he signed two petitions demanding political reform in the ultra-conservative kingdom, where political parties are banned.

Abulkhair has created a group on Facebook -- Monitor of Human Rights in Saudi -- which has nearly 7,000 members.