British officials are seeking information on reports that authorities in Tehran have detained a British-Iranian national and an Iranian employee of the British Council.
The British Foreign Office on May 2 told the Associated Press it was "urgently seeking information from the Iranian authorities" after receiving reports of the detention of Iranian-British national Mahan Abdein.
Separately, the British Council said it was aware of the detention of a London-based staffer, identified as Iranian national Aras Amiri, who it said had traveled to Iran to visit family.
"Despite an assertion that this individual has traveled to Iran for work this is not the case," said the council, which promotes cultural ties between Britain and other countries.
The news website IranWire first reported the two detentions.
The site, created by Iranian-Canadian journalist and former detainee Maziar Bahari, said Amiri, 32, had been arrested on March 14 but that her parents declined to go public until now about her detention.
The website said Abedin might have been arrested in connection with Abbas Edalat, a British-Iranian professor detained on April 25 on charges of violating security laws.
The latest two arrests have not been acknowledged by Iranian authorities.
Several British citizens are currently being held in Iran. The Islamic Revolutionary Guards Corps (IRGC) has arrested around 30 dual nationals over the past three years, most of them on charges of spying.
Since the country does not recognize dual citizenship, access to foreign embassies by dual citizens held there is limited.