An Iranian court on Tuesday sentenced one person to death for spying for the US and jailed another three.
"Two people are sentenced to 10 years in prison for spying for the United States and another for spying for the United Kingdom," judiciary spokesman Gholamhossein Esmaili told the news website Mizan.
Mr Esmaili said an appeal had been lodged against the verdict for the person sentenced to death.
He said the other two men, Ali Nefriyeh and Mohammad Ali Babapour, received final 10-year sentences for spying for the CIA and were ordered to repay $55,000 (Dh202,000) they received.
The man accused of spying for the UK was Mohammad Amin Nassab, Mr Esmaili said.
Three other people were sentenced to lengthy prison terms on spying charges in August.
The announcement comes amid heightened tension between Iran and western nations, including the US and UK.
US President Donald Trump withdrew from Iran's 2015 nuclear deal with major world powers and reimposed sanctions that have crippled Iran's economy.
In July, Iran said it arrested 17 CIA spies who sent Washington information on Iran's nuclear and military activities.
The arrests took place this year and those taken into custody worked on "sensitive sites" in the country's military and nuclear centres, Iranian officials said.
Some of them had been sentenced to death, officials said, but they did not say how many.
It was not immediately clear if any of the cases on Tuesday were linked to Iran's announcement in July.
Mr Esmaili also confirmed that the authorities had detained Iranian-British anthropologist Kameel Ahmady for suspected ties to institutes linked with foreign intelligence services.
Mr Ahmady's case is in the initial investigation phase, he said. This was the first time Iran had confirmed his arrest.
His wife, Shafagh Rahmani, and activists say he has been detained since August.
The confirmation came less than three months after the detention of Franco-Iranian academic Fariba Adelkhah was publicised.
"It is true that this person [Mr Ahmady] was arrested," Mr Esmaili said in Tehran.
French anthropologist Christian Bromberger wrote in August that Mr Ahmady was "recently arrested", in an article on The Conversation website.
Mr Ahmady is the author of a book called In the Name of Tradition: Female Genital Mutilation in Iran.
He was subject to a "preliminary investigation" on suspicion of "links to foreign countries and institutes affiliated with foreign services", Mr Esmaili said.
On July 15, the French authorities announced that Ms Adelkhah had been arrested in Iran.
A specialist in Shiite Islam, she is the research director at the Centre for International Studies and Research at Sciences Po university in Paris.
Mr Esmaili confirmed her arrest the next day.
She is the latest dual national to be detained in Iran. In August, Iran said it convicted Aras Amiri, who had worked for the British Council, on spying charges.
The British Council is a non-political organisation that works in education, arts and culture.
Ms Amiri has been in jail for the past year while her case was under investigation. She was sentenced to 10 years.
Another British-Iranian woman held in Tehran, Nazanin Zaghari-Ratcliffe, is serving a five-year jail sentence for allegedly planning the “soft toppling” of Iran’s government while traveling with her young daughter.
Mrs Zaghari-Ratcliffe, who worked for the charity arm of Thomson Reuters, was arrested in April 2016. Her sentence has been widely criticised.