The citizen is said to hold dual nationality of U.S. and another country.

An Iranian news agency is reporting that the brother of President Hassan Rouhani has been detained over financial matters.

The semi-official Tasnim news agency quoted Judiciary spokesman Gholamhosein Mohseni Eje'i on Sunday saying that Hossein Fereidoun had been detained and could be released on bail.

Mr. Fereidoun is the brother and a top aide to moderate President Rouhani, who changed his surname from Fereidoun years ago.

Mr. Eje'i also reported that a United States citizen accused of “infiltration” in Iran has been sentenced to 10 years in prison, a spokesman for the judiciary said on Sunday.

“The person was identified and arrested by the intelligence forces. The court has sentenced the person to 10 years,” Mr. Eje'i said in a televised press conference.

The individual, whose name was not provided, has appealed the sentence, he added.

Dual nationality

The foreigner holds dual nationality of the United States and another country, he said, promising to give more details once the appeals court confirms the sentence.

In January, Tehran’s chief prosecutor said as many as 70 “spies” were serving sentences in the city's prisons -- the identities of only a handful of which have been made public.

Most are thought to be Iranians who hold another passport from Europe or the United States.

In October, US-Iranian business consultant Siamak Namazi and his 80-year-old father Baquer, a former UNICEF official, were given 10 years in prison for “espionage and collaboration with the American government.”