|Parvaz was detained by Syrian authorities on arrival in Damascus on April 29 [Photo:Megan MacKenzie]
Al Jazeera journalist Dorothy Parvaz has now been missing for two weeks, and Syrian authorities say that she has been deported to Iran.
Parvaz, who holds Iranian, American and Canadian citizenship, has been missing since she arrived at Damascus airport on April 29 to cover protests in Syria.
Syrian officials had previously told Al Jazeera the 39-year-old was being held in the Syrian capital and would be released.
"We have now received information that she is being held in Tehran," an Al Jazeera spokesman said in a statement on Wednesday.
"We are calling for information from the Iranian authorities, access to Dorothy, and for her immediate release. We have had no contact with Dorothy since she left Doha on April 29 and we are deeply concerned for her welfare."
In a statement issued on Tuesday, the Syrian embassy in Washington DC said Parvaz had attempted to enter Syria illegally on an expired Iranian passport and subsequently been extradited to Iran.
On May 1, Parvaz was "escorted by the Iranian consul to Caspian Airlines flight 7905 heading to Tehran," the statement said.
Iran's foreign minister, Ali Akbar Salehi, told Al Jazeera on May 2 that he had no knowledge of Parvaz’s whereabouts and urged Syria to look into the case.
Parvaz's family has also called for the journalist to be released.
"Dorothy is a dearly loved daughter, sister and fiancée, and a committed journalist," they said in a statement released earlier in the week.
"It is now nearly two weeks since she was detained. We appeal once again for Dorothy to be released immediately and returned to us."
Parvaz is an experienced journalist who joined Al Jazeera in 2010.
She graduated from the University of British Columbia, obtained a master's degree from the University of Arizona, and held journalism fellowships at both Harvard and Cambridge.
She previously worked as a columnist and feature writer for the Seattle Post-Intelligencer.