The Iranian Intelligence Ministry announced it had dismantled an Israeli spy ring and arrested suspects related to the assassination of an Iranian nuclear scientist in January, the semiofficial Fars News Agency reports.
Massoud Ali Mohammadi, an Iranian physics professor at Tehran University, was killed when an explosive device denoted in front of his home as he left for work in January 2010.
Iranian media said shortly after the blast that a monarchist group, the Royal Association of Iran, claimed responsibility for the attack.
Ali Larijani, the speaker of the Iranian Parliament, downplayed the claims of responsibility saying Tehran had evidence to suggest foreign intelligence agencies were behind the attack.
The Intelligence Ministry added that it uncovered "very important and sensitive" information about Mossad activity in Europe that was connected to work inside the Islamic republic.
Tehran last week called on the International Committee of the Red Cross to help ascertain what happened to a general who allegedly died in Israel. The general, Ali Reza Asgari, allegedly gave Western intelligence officers information about Iran's nuclear activity.