Iranian president's brother arrested in high-profile corruption case

President Hassan Rouhani's brother has been arrested as part of a high-profile corruption case, according to Iranian authorities, who earlier sentenced a US dual national to prison on spying charges.

State television quoted deputy judiciary chief Gholamhossein Mohseni Ejei as saying Hossein Fereydoun, who is also a close adviser and gatekeeper to Rouhani, was summoned for questioning on Saturday in a case in which he faces unspecified financial charges. He was later detained.

"Multiple investigations have been conducted regarding this person, also other people have been investigated, some of whom are in jail.

"Yesterday, bail was issued for him but because he failed to secure it he was referred to prison," Ejeie said, adding that he would be released if he secures bail, pending trial.

Some Rouhani supporters have interpreted the charges against Fereydoun, a senior diplomat who took part in the talks that led to a 2015 nuclear deal between Iran and world powers, as a move by the hardline judiciary to discredit the president.

Conservatives have demanded Fereydoun be put on trial, accusing him of receiving zero-interest loans and influencing the appointment of a bank director whom Rouhani had to dismiss for taking an enormous salary.

US dual national sentenced for spying

Earlier in the day Mohseni Ejei announced that a US dual national had been sentenced to 10 years in jail on spying charges, the latest case of dual nationals held on security charges in the country.

The spokesman did not name the person or give details on when the sentence was passed but said the person was a citizen of the United States and an unnamed country other than Iran.

"This person, who was gathering information and was directly guided by America, was sentenced to 10 years in prison, but the sentence can be appealed," spokesman Gholamhossein Mohseni Ejei said on state television.

It was not immediately clear whether Mohseni Ejei was referring to Nizar Zakka, a Lebanese citizen with permanent US residency, who has been sentenced to 10 years in prison and fined $4.2mn after he was found guilty of collaborating against the state, according to his US-based lawyer who spoke to reporters in September.

Several Iranian dual nationals from the United States, Britain, Austria, Canada and France have been detained in the past year and are being kept behind bars on charges including espionage and collaborating with hostile governments.