( CNN ) -- An outspoken Saudi human rights advocate who was imprisoned without charge for nearly eight months was freed this weekend , according to a fellow human rights activist . Matrook al-Faleh , shown in 2004 , was seized after he criticized prison conditions , says Human Rights Watch . Matrook al-Faleh `` is doing very well '' after leaving Al-Hayer maximum security prison near Riyadh , Saudi Arabia , late Saturday , said colleague Mohammed al-Qahtani , who visited al-Faleh on Sunday . `` He is very healthy and his morale is quite high -- surprisingly after eight months , '' said al-Qahtani . Both men are Saudi college professors . It 's unclear why al-Faleh was arrested . A Human Rights Watch report condemning the arrest and urging al-Faleh 's release said his detention came two days after he publicly criticized conditions in a prison where two other Saudi human rights activists are imprisoned . It was also unclear why he was held for so long . According to al-Qahtani , Saudi law mandates that no one can be held for more than six months without charge . `` The criminal code says you charge him or release him , but sometimes they do not respect the law they issued , '' al-Qahtani said . An official at the Saudi Interior Ministry said he had no details about al-Faleh 's case . Jamila al-Uqla , al-Faleh 's wife , spoke to CNN in May , shortly after her husband was detained . She described how her husband had been arrested without charge and interrogated repeatedly . Al-Faleh had decided to go on a hunger strike to demand that he be told why he was being held , she said . His wife stressed that she and al-Faleh are patriotic Saudis . `` My husband is transparent and does n't hide anything , '' said al-Uqla . `` He says whatever he sees . He has loyalty to his country and the interests of his country . '' It was not Al-Faleh 's first brush with the Saudi legal system . Al-Faleh , Abdullah al-Hamid and Ali al-Dumaini , who runs a Saudi discussion Web site , were arrested in 2004 for circulating a petition meant for then-Crown Prince Abdullah which called for a constitution guaranteeing basic human rights . A court sentenced al-Faleh , Abdullah al-Hamid and Ali al-Dumaini , to six , seven and nine years respectively . But King Abdullah pardoned them in August 2005 , Human Rights Watch said .
Saudi professor Matrook al-Faleh imprisoned for eight months without charge . He was released from a prison near Riyadh late Saturday , fellow activist says . Rights group : Al-Faleh 's detention came after he criticized prison conditions .