( CNN ) -- Iranian authorities on Tuesday released one of three people detained along with Washington Post reporter Jason Rezaian last week , a source close to the family of the released detainee told CNN on Wednesday . The released detainee is the husband of an Iranian-American photojournalist who remains in custody with Rezaian and his wife , according to the source . Authorities have yet to identify the photojournalist , and Iranian officials have yet to explain why the journalists were detained . According to The Washington Post , Rezaian , 38 , holds American and Iranian citizenship . He has been the paper 's Tehran correspondent since 2012 . His wife , Yeganeh Salehi , is an Iranian citizen who has applied for U.S. permanent residency . She is a correspondent for the UAE-based newspaper the National , The Post said . Gholam-Hossein Esmaili , the director general of the Tehran Province Justice Department , has been quoted by Iran 's official IRNA news agency as saying that a `` Washington Post journalist has been detained for some questions and after technical investigations , the judiciary will provide details on the issue . '' He did not specify on what grounds the correspondent , whom he did not name , was being held . Iranian security forces are vigilant about all kinds of enemy activities , Esmaili added , according to IRNA . Rights activists and fellow journalists have condemned the arrests of the journalists and demanded their release . According to research by the Committee to Protect Journalists , there are 35 journalists in prison in Iran . Rezaian 's mother made a videotaped plea for the release of her son and daughter-in-law Tuesday . She warned that his health would be compromised without medication for high blood pressure . `` I do not know where my son and daughter-in-law are , '' Rezaian 's mother said in a video clip posted on the Washington Post 's website . `` As a mother , I am extremely worried about their well-being . '' Rezaian 's mother noted that her son 's love for Iran `` is so infectious that he has made a career out of sharing its beauty with others . '' `` Since he was a little boy , my son loved Iran . Jason moved to Iran to live and work full-time , '' she said . '' `` I love my son and daughter , and I am proud of their commitment to journalism . I know their standards for truth and excellence in journalism guide them both professionally and personally . I humbly ask those who continue to detain my son and daughter to please release them and allow our family to be reunited and my fears for their safety to subside . '' In a statement Thursday , Washington Post foreign editor Douglas Jehl said , `` we are deeply troubled by this news and are concerned for the welfare of Jason , Yeganeh and two others said to have been detained with them . '' He described Rezaian as `` an experienced , knowledgeable reporter who deserves protection and whose work merits respect . '' Four journalists detained in Iran , three of them Americans .
Reporter 's mother delivers video statement on Washington Post website . The detentions have spurred outrage among other journalists , rights activists . Jason Rezaian has been the paper 's Tehran correspondent since 2012 .