Ali Aqazadeh Dafsari, a member of parliament's national security and foreign policy panel, said the drone was near the nuclear facility when it was downed by the Islamic Revolutionary Guards Corps' air defense units, government-backed Fars News Agency reported Wednesday.
Dafsari said the drone was sent to identify the location of the Fordo nuclear enrichment plant and collect information about the nuclear facility for the CIA.
Earlier this year, a senior Iranian military official said several drones were shot down over the Persian Gulf and Iran has targeted the pilotless aircraft for the last seven years.
Western leaders maintain Iran is developing nuclear weapons capability. Iranian officials say its nuclear program is for peaceful purposes.