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Story highlights

Clinton received emails mentioning Amiri on her controversial personal email server

Trump and other Republicans have criticized Clinton's actions

(CNN) —  

The execution of an Iranian nuclear scientist accused of spying for the US is reverberating from Tehran to the presidential campaign trail.

Critics, including opponent Donald Trump, are slamming former Secretary of State Hillary Clinton for having received emails mentioning him on her controversial personal email server.

Trump took to Twitter on Monday to link Clinton to Shahram Amiri’s death, writing, “Many people are saying that the Iranians killed the scientist who helped the U.S. because of Hillary Clinton’s hacked emails.”

The emails mentioning Amiri were were part of a tranche released by the State Department last year pursuant to a Freedom of Information Act request in the wake of the revelation that Clinton used a personal server to conduct official business. The FBI has said there is no direct evidence the server was hacked, noting such evidence would be hard to come by.

The Clinton campaign fired back at GOP attacks on Monday, releasing a statement even before Trump’s tweet accusing the GOP presidential nominee of using “increasingly desperate rhetoric to attack Hillary Clinton and make absurd accusations because they have no ideas for the American people.”

The State Department Monday denied any connection between the emails mentioning the delicate case and Amiri’s execution.

RELATED: Iran: Nuclear scientist executed for spying for ‘Great Satan’ US

State Department spokeswoman Elizabeth Trudeau told reporters “there was public reporting on this topic back in 2010,” referencing a news conference in which Clinton mentioned the scientist.

“This is not something that became public when the State Department released those emails,” she added, noting that none of the emails mentioning Amiri were classified or retroactively classified as such upon their release – as some emails sent to Clinton were – a sign the Amiri material was not considered too sensitive to be made public.

“We’re not going to comment on what may have led to this event,” Trudeau added, referring to Amiri’s prosecution and execution.

Amiri was initially greeted as a hero upon returning to Iran six years ago. At the time, he had claimed he was kidnapped by American spies while on a pilgrimage to Saudi Arabia, saying that he had been offered millions of dollars to spy on the US’s behalf but had opted to turn it down. While in the US, he seemed to appear in one video saying he was kidnapped but later in another video said he was there by choice.

On Sunday, however, Iran’s Judiciary Ministry announced Amiri had been hanged for sharing Iran’s nuclear secrets with the enemy.

“He was put on trial and was convicted and sentenced to death,” Iran judiciary spokesman Gholam-Hossein Mohseni-Ejei told reporters Monday.

“(He) not only did not make up for his crime and did not repent, he also tried to send information from prison. Anyway, after due process, he received his punishment,” he added.

US officials have said that Amiri willingly defected but then changed his mind, choosing to return to Iran to be with his family. Officials suspect he feared for the safety of his family living in Iran.

“Mr. Amiri has been in the United States of his own free will and he is free to go,” Clinton said at a July 2010 press conference.

RELATED: Cryptic Clinton emails may refer to Iranian scientist

But the appearance of veiled references to the Amiri case in Clinton’s emails has fueled another round of recriminations over her private email account.

One message, written by Richard Morningstar, acting special envoy of the US secretary of state for Eurasian energy at the time, was sent to Clinton on July 5, 2010, just days after the videos purportedly of Amiri were posted online and less than two weeks before he left the US.

The email appears to reference Amiri’s hesitation at continuing on as a defector and his wish to leave the US.

“Per the subject we discussed, we have a diplomatic, ‘psychological’ issue, not a legal issue,” Morningstar wrote. “Our friend has to be given a way out. We should recognize his concerns and frame it in terms of a misunderstanding with no malevolent intent and that we will make sure there is no recurrence. Our person won’t be able to do anything anyway. If he has to leave, so be it.”

After arriving in Tehran, Amiri repeated his allegation that he was kidnapped by American intelligence agents.

Other Clinton critics accused her of being careless with sensitive information.

Republican Sen. Tom Cotton of Arkansas drew a link between the emails and Amiri’s execution Sunday, saying on CBS’ “Face the Nation,” “In the emails that were on Hillary Clinton’s private server, there were conversations among her senior advisors about this gentleman.”

He continued, “That goes to show just how reckless and careless her decisions were to put that kind of highly classified information on a private server, but I think her judgment is not suited to keep this country safe.”

CNN’s Laura Koran and Dan Merica contributed to this report.