Authorities in Switzerland and Austria say they have started investigating possible espionage at nuclear talks involving Iran and six major powers that were hosted by both countries.
The announcements come after Russian computer security company Kaspersky Lab said on June 10 that a computer virus was used to hack into venues linked to the negotiations.
Kaspersky said it found the software in three European hotels used in the negotiations, and also on Kaspersky's own computers.
Both Kaspersky and U.S. security company Symantec said the virus shared some programming with previously discovered espionage software called Duqu, which security experts believe was developed by Israelis.
"Most notably, some of the new 2014-2015 infections are linked to the...venues related to the negotiations with Iran about a nuclear deal," the statement said.
The talks between Iran, the United States, Russia, China, Britain, France, and Germany have been held in Geneva, Lausanne, Montreux, Munich, and Vienna.
Israeli Deputy Defense Minister Eli Ben-Dahan denied on June 11 his country carried out the cyberattack.
In February, the United States accused Israel of using selective leaks from the talks to distort the U.S. position.
Israel has denounced the diplomatic opening to Iran, saying it doubts any agreement arising from the talks will truly restrain Iran's nuclear ambitions.
Based on reporting by dpa and AFP