For decades, Switzerland has maintained a neutral stance on the global stage, but in Iran, it plays a vital role. Since diplomatic ties between Washington and Tehran were severed following the 1979 Islamic Revolution, Switzerland has served as the official representative of U.S. interests in Iran. Swiss diplomats in Tehran often act as discreet intermediaries, passing sensitive messages between the two adversaries.

In recent years, however, a series of mysterious incidents involving Swiss nationals in Iran—two diplomats dead, another wounded, and a tourist allegedly driven to suicide in prison—has sparked growing concern in Bern. A new investigation by Swiss public broadcaster SRF, published Monday, reveals that suspicions are mounting within the diplomatic corps: Iranian intelligence, and possibly the Revolutionary Guards, may have been behind the attacks.

The first incident occurred in May 2021, when Sylvie Brunner, the Swiss deputy ambassador in Tehran, fell to her death from the 17th floor of a high-rise building in the Iranian capital. Initially, many in Switzerland accepted Iran’s claim that Brunner suffered from mental health issues and took her own life. But Iranian first responders at the scene had said there was no clear reason to suspect suicide. That claim was later retracted, and the official who made it was dismissed. Iran's official version remained that Brunner had died by suicide.

Swiss authorities conducted their investigation and closed the case at the end of 2024 due to a lack of evidence. But the SRF report now casts new doubt on the circumstances of her death. Brunner’s brother told investigators that Iranian intelligence agents had visited her apartment, leaving behind clear boot prints—a deliberate warning that she was being watched. According to the report, confidential sources say Swiss officials were aware for some time that Brunner was being harassed and intimidated by Iranian operatives but were unable to act, as Swiss police have no jurisdiction in Iran.

Investigators also noted that, while a suicide note was found in her apartment, it was unsigned. A Swiss forensic expert told SRF that while suicide was possible, it could not be ruled out that Brunner was pushed from her balcony by one or more individuals. Additional suspicions arose when her body was returned to Switzerland, missing the brain, heart, and other organs, parts that could have provided key forensic evidence.

The second mysterious case came in 2023. A Swiss military attaché stationed in Iran collapsed from sudden illness, sustaining severe head and abdominal injuries, and fell unconscious. He was flown back to Switzerland, where he later died of his wounds. The SRF report revealed that the man was secretly a Swiss intelligence operative, and some experts believe he may have been exposed while on a mission.

Swiss intelligence officials declined to comment on the allegations.

He added that he doesn’t know exactly why she was killed, but emphasized the Revolutionary Guards' deep paranoia: “They view the Swiss embassy as a point for the Americans. In Iran, they believe some embassy staff are working for the CIA.” police state like Iran, such violent street crimes are rare, raising further suspicions.

Reporters concluded that the three incidents may be linked. A former Iranian intelligence officer who defected to Germany told SRF: “In 2021, I was in Iran. My colleagues in the intelligence unit spoke openly about the diplomat who fell from her balcony. They told me it was an operation by the Revolutionary Guards’ intelligence service. It was a murder—an espionage mission that went wrong.”

He added that he doesn’t know exactly why she was killed, but emphasized the Revolutionary Guards' deep paranoia: “They view the Swiss embassy as a point of penetration for the Americans. In Iran, they believe some embassy staff are working for the CIA.”

A fourth incident took place earlier this year, not involving a diplomat, but a Swiss tourist in his 60s. He was arrested by Iranian authorities and accused of espionage after allegedly taking photos of a sensitive military site and collecting soil samples nearby. He was imprisoned and died two months later, reportedly by suicide. Throughout his detention, Swiss officials were denied access to him due to Iran’s insistence that he was a spy.

His body was eventually returned to Switzerland, where an autopsy was performed. The results have not yet been made public.