A Chinese-American has been handed at least 10 years of jail in Iran on spying charges, officials in Tehran said.

Gholamhossein Mohseni-Ejeie, spokesman for the Iranian judiciary, said in a weekly press briefing in Tehran on Sunday (16 July) that the China-born US citizen identified as Xiyue Wang was jailed for being "an infiltrating American agent". Wang's conviction came a year after his arrest in August 2016 as he tried to leave the country.

The 37-year-old's sentencing was announced on Mizan Online, a news agency affiliated with the judiciary.

It said that Wang, who is a researcher from Princeton University, was part of "an infiltration project" that was required to gather "highly confidential articles" for US and British institutions including the US State Department, Princeton University, Harvard Kennedy School and the British Institute of Persian Studies.

"Before his arrest he was able to digitally archive 4,500 pages of the country's documents while under covert surveillance," the agency added.

Mohseni-Eje'i said Wang entered the country "through a special connection but the ministry of intelligence identified him and arrested him". It "became clear that he was involved in the infiltration project", he added and the court sentenced him to 10 years.

But he added that the sentence could be appealed, the Guardian reported.

Gholamhossein Mohseni-Ejeie
Gholamhossein Mohseni-Ejeiei, spokesman for the Iranian judiciary, said Xiyue Wang was jailed for being 'an infiltrating American agent' - File photoREUTERS/Stringer

Meanwhile, the US Department of State without mentioning any specific person, has called on Iran to release all foreign citizens it is holding "unjustly... so they can return to their families".

"The Iranian regime continues to detain US citizens and other foreigners on fabricated national-security related changes," a press statement from the state department said.

"The safety and security of US citizens remains a top priority. All US citizens, especially dual nationals considering travel to Iran, should carefully read our latest travel warning."

It was said that Iran has a history of making such allegations against foreign nationals, especially those holding dual-citizenship.

Earlier, Tehran had imprisoned an Iranian-American Washington Post reporter, Jason Rezaian, for 18 months on espionage charges. However, he was released in January 2016 and Rezaian has since sued the Iranian government, accusing it of hostage-taking and torture.

Princeton University has come out in support of Wang and said: "Xiyue Wang is a fourth-year doctoral candidate ... in the Department of History at Princeton University. We were very distressed to learn that charges were brought against him in connection with his scholarly work, and to learn of the subsequent conviction and sentence.

"We cannot comment more at the present time, except to say that the university continues to do everything it can to be supportive of Mr Wang and his family."