Sakineh Mohammadi-Ashtiani's stoning case, which is linked to the latest arrests in Iran, has sparked protests [AFP]

Iran has arrested two foreigners who entered the country on tourist visas, allegedly to interview the son of a woman facing execution by stoning, according to Iran's public prosecutor.

The two foreigners were reportedly captured by security services on Monday, after an interview with the son of Sakineh Mohammadi-Ashtiani, the woman who faces death for alleged adultery.

Ashtiani's case has sparked protests around the world, with critics accusing the Iranian government of sexism and brutality. 

"Based on the official statement released by the judiciary, these two foreign nationals entered the country on tourist visas, not working visas," Ghanbar Naderi of Iran Daily, an official government newspaper, told Al Jazeera.

"Basically, they are not journalists. When they were arrested they did not produce any document to prove they were journalists. If you are a journalist, you need to get permission from the government to conduct any reports."

'Fugitive' contacts

Gholam Hossein Mohseni Ejeie, the public prosecutor, hinted that the detainees may be two Germans, linking them to an Iranian human-rights activist living in Europe.

Ejeie said the arrested foreigners were were put in contact with Ashtiani's family by a "fugitive", alluding to Mina Ahadi, the Germany-based founder of the International Committee against Execution and Stonings.

Iran Daily's Naderi said the arrests will make it harder for "genuine journalists" who want to "come to this country and conduct their own reports on the situation in this part of the world".

In a related case, the Iranian government cancelled the press accreditation for a Spanish reporter, her employer, the Spanish daily El Pais, said on Monday.

Angeles Espinosa was not given an official explanation on why authorities revoked her accreditation, but the decision could to be linked to an interview she conducted with the son of the late dissident Grand Ayatollah Hossein Ali Montazeri in July.

She was detained and stripped of her press card in Qom, which is considered a holy city in Iran, after interviewing Ahmad Montazeri.

Foreign correspondents require official permission to travel outside Tehran, the capital, and are barred from leaving their offices to report on demonstrations and other unofficial political events.