The revelation comes ahead of the June 30 deadline for a historic agreement between Iran and world powers on rolling back Tehran's nuclear program in exchange for easing the hard-hitting international sanctions.
Austria said Thursday it too was investigating possible spying at the Palais Coburg hotel, the location of many rounds of the talks, an interior ministry spokesman told AFP.
The talks between Iran and the world powers have been held in several Swiss hotels: the Palais Wilson and Intercontinental in Geneva, the Beau Rivage in Lausanne and the Royal Plaza in Montreux.
Thursday's announcement came after a Russian-based security firm said Wednesday the malware dubbed Duqu, which is a sophisticated spy tool, appeared to have been used to spy on nuclear negotiations with Iran.
Russia’s Kaspersky Lab cybersecurity firm discovered a computer virus they allege is traced to Israeli intelligence and targets the hotels used for the Iranian nuclear program talks, media reported Wednesday.
