What started out as scattered, seemingly isolated incidents is now raising serious red flags in Switzerland.
Over the past four years, several suspicious deaths and attacks have occurred involving Swiss diplomats and citizens in Iran — and now, the Swiss intelligence service believes they may have been assassinations.
The concern isn’t just theoretical.
It’s rooted in a troubling series of cases, including a mysterious fall, a deadly collapse, a stabbing, and even a prison suicide — all involving Swiss nationals in Iran.
A Fatal Fall That Raised Eyebrows
Back in 2021, Sylvie Brunner, the deputy ambassador of Switzerland to Tehran, died under chilling circumstances.
According to a former officer of Iran’s Islamic Revolutionary Guard Corps (IRGC), Brunner was pushed from her 17th-floor balcony.
Iranian authorities, however, insisted it was suicide.
Whispers within the diplomatic and intelligence communities suggest something darker.
The same former IRGC officer alleged that Brunner may have died during a botched spy operation.
He claimed some Iranian officials believed Swiss embassy staff were working with the CIA.
Initially, Iranian responders said there was no clear indication that Brunner was suicidal.
But when an official voiced doubts, they were quickly dismissed — and their statements retracted.
Clues That Something Wasn’t Right
Sylvie Brunner’s death never sat well with her family or some Swiss investigators.
Her brother, Vincent, told Swiss broadcaster SRF that he always believed she was murdered.
He revealed that shortly before her death, she had noticed boot prints in her apartment — a clear sign someone was watching her.
Brunner had also confided in colleagues that she was being followed and harassed by Iranian operatives.
But Swiss police stationed there were reportedly powerless to intervene.
When her body was finally returned to Switzerland, some of her key organs had been removed, making it impossible to perform a full toxicology report.
A Swiss-commissioned forensic review couldn’t rule out foul play, suggesting “one or two people” may have been involved.
More Suspicious Incidents Followed
Just two years later, in 2023, a Swiss defence attaché collapsed in a Tehran hotel.
He suffered severe head and abdominal injuries and died months later after returning to Switzerland.
He was believed to have been on a sensitive assignment — yet again, Iranian authorities called it a “natural death.”
And that wasn’t all. Just months afterward, another Swiss Embassy employee was stabbed and shot in the hand while walking to work.
Iranian officials said it was a robbery.
But critics questioned this theory, pointing out that such violence is rare in Tehran, especially in heavily patrolled zones.
A Tourist’s Mysterious Death in Custody
In January 2025, the pattern continued — this time involving a Swiss tourist.
The man, in his 60s, reportedly hanged himself in Semnan prison after being arrested for espionage.
Iranian media announced the suicide, but his autopsy results haven’t been made public.
Switzerland’s Foreign Ministry has said they’re working to clarify all these deaths, but added that their ability to investigate is limited while on Iranian soil.
Swiss Intelligence Sounds the Alarm
The Federal Intelligence Service (FIS) of Switzerland is now treating these incidents as part of a broader threat to their diplomatic corps in Iran.
Officials believe Iran sees the Swiss embassy as a proxy for the United States, especially since Switzerland has represented American interests in Iran since the 1979 Islamic Revolution.
According to the FIS, Iran has ramped up efforts to expose and intimidate Swiss personnel, particularly amid heightened regional tensions.
While Russia, China, and North Korea have also increased their spying efforts against Switzerland, it’s Iran’s aggressive posture that’s causing the most concern.
Calls for Justice and Transparency
Back home, Swiss politicians are demanding answers.
Some have called for an international investigation into these troubling deaths and attacks, arguing that the country cannot ignore such glaring warning signs.
Despite this, no formal inquiry has been launched yet.
The Brunner family is considering civil action after Swiss prosecutors closed the criminal case for lack of evidence.
A Dangerous Role in a Fragile Diplomatic Dance
Switzerland’s unique position as a diplomatic bridge between Iran and the United States has placed its envoys in a precarious spot.
What once seemed like isolated tragedies now appear to form a pattern — one that has left Swiss intelligence and families back home searching for justice, and a haunting question: are their diplomats being hunted?