A media watchdog has called on Turkey to halt the expulsion of an Iranian journalist sentenced to prison for alleged activities against the regime after criticizing Tehran's response to the coronavirus pandemic.

The U.S-based Committee To Protect Journalists (CPJ) said in a statement on January 18 that Mohammad Mosaed contacted the group a day earlier saying he had been detained by Turkish border police after crossing into Turkey from Iran at the eastern border city of Van.

Mosaed told the CPJ that he fled to Turkey after being summoned by Iranian authorities to begin serving his prison sentence in two days’ time.

He said the Turkish police took him to hospital for medical treatment, and told him he would soon be handed back to Iranian border guards.

Mosaed was sentenced in August by an Iranian court to four years and nine months in prison on charges of "colluding against national security" and "spreading propaganda against the system" after posting a tweet critical of the government's tackling of the outbreak.

The CPJ at the time described the ruling as a further attempt by Iranian authorities to try to "suppress the truth."

Mosaed was first detained in November 2019 in connection with messages he had posted on social media during an Internet shutdown implemented by the government amid widespread protests over high gas prices.

He was honored with the CPJ’s 2020 International Press Freedom Award in November.

“We believe that Mohammad Mosaed has a well-founded fear of persecution should he be returned to Iran,” said CPJ Middle East and North Africa Coordinator Sherif Mansour said in the statement.

"We urge Turkish authorities to respect their obligations under international law; to refrain from deporting Mosaed; to consider any request for political asylum that Mosaed may make; and to assure Mosaed's rights are protected through due process of law."

CPJ said phone messages to the office of the Turkish province of Van, where Mosaed is being detained, were not immediately returned.