Yet Western analysts said Ali-Mohammadi, a 50-year-old Tehran University professor, had little, if any, role in Iran's sensitive nuclear program. A spokesman for Iran's Atomic Energy Organisation said at the time he was not involved in its activities.
The most recent attack on an Iranian scientist occurred in January. Mostafa Ahmadi-Roshan - a deputy director of the Natanz uranium enrichment facility - was killed when a magnetic bomb planted on his vehicle detonated.
Tehran has accused Israel and the United States of assassinating four Iranian scientists in order to sabotage its controversial nuclear program. Washington has denied any U.S. role, while Israel has declined to comment.
Last month, Iranian intelligence officials said they had arrested 15 people they called a "major terror and sabotage network with links to the Zionist regime". The group had plotted to assassinate an Iranian scientist in February, the authorities said.
Iran denies Western accusations it is seeking to develop a nuclear weapons capability, but major powers are pushing Tehran to become more transparent and cooperative ahead of talks later this month.
British Foreign Secretary William Hague on Monday warned the European Union would impose tougher sanctions on Iran if it failed to take concrete steps to allay international concerns over its nuclear program.